[Broker] Refine topic level backlog quota policies warning log

[gaoran10]

Motivation

Currently, if the TopicPolicies isn't initialized completely, the topic gets backlog quota will print the error log stack, this is not necessary, because after the TopicPolicies initialized, the topic level backlog quota will come into effect.

15:24:01.962 [bookkeeper-ml-workers-OrderedExecutor-2-0] WARN  org.apache.pulsar.broker.service.BacklogQuotaManager - Failed to read topic policies data, will apply the namespace backlog quota: topicName=persistent://public/ns3/t1
org.apache.pulsar.broker.service.BrokerServiceException$TopicPoliciesCacheNotInitException: Topic policies cache have not init.
	at org.apache.pulsar.broker.service.SystemTopicBasedTopicPoliciesService.getTopicPolicies(SystemTopicBasedTopicPoliciesService.java:148) ~[org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at org.apache.pulsar.broker.service.BacklogQuotaManager.getBacklogQuota(BacklogQuotaManager.java:85) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at org.apache.pulsar.broker.service.persistent.PersistentTopic.getBacklogQuota(PersistentTopic.java:2172) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at org.apache.pulsar.broker.service.persistent.PersistentTopic.isBacklogQuotaExceeded(PersistentTopic.java:2181) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at org.apache.pulsar.broker.service.ServerCnx.lambda$handleProducer$20(ServerCnx.java:1100) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:714) [?:?]
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) [?:?]
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:2073) [?:?]
	at org.apache.pulsar.broker.service.BrokerService$3.lambda$openLedgerComplete$2(BrokerService.java:1125) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at java.util.concurrent.CompletableFuture.uniRunNow(CompletableFuture.java:815) [?:?]
	at java.util.concurrent.CompletableFuture.uniRunStage(CompletableFuture.java:799) [?:?]
	at java.util.concurrent.CompletableFuture.thenRun(CompletableFuture.java:2121) [?:?]
	at org.apache.pulsar.broker.service.BrokerService$3.openLedgerComplete(BrokerService.java:1111) [org.apache.pulsar-pulsar-broker-2.7.3.jar:2.7.3]
	at org.apache.bookkeeper.mledger.impl.ManagedLedgerFactoryImpl.lambda$asyncOpen$8(ManagedLedgerFactoryImpl.java:425) [org.apache.pulsar-managed-ledger-2.7.3.jar:2.7.3]
	at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:714) [?:?]
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) [?:?]
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:2073) [?:?]
	at org.apache.bookkeeper.mledger.impl.ManagedLedgerFactoryImpl$2.initializeComplete(ManagedLedgerFactoryImpl.java:397) [org.apache.pulsar-managed-ledger-2.7.3.jar:2.7.3]
	at org.apache.bookkeeper.mledger.impl.ManagedLedgerImpl$3.operationComplete(ManagedLedgerImpl.java:476) [org.apache.pulsar-managed-ledger-2.7.3.jar:2.7.3]
	at org.apache.bookkeeper.mledger.impl.ManagedLedgerImpl$3.operationComplete(ManagedLedgerImpl.java:466) [org.apache.pulsar-managed-ledger-2.7.3.jar:2.7.3]
	at org.apache.bookkeeper.mledger.impl.MetaStoreImpl.lambda$getCursors$8(MetaStoreImpl.java:122) [org.apache.pulsar-managed-ledger-2.7.3.jar:2.7.3]
	at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:714) [?:?]
	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:478) [?:?]
	at org.apache.bookkeeper.common.util.OrderedExecutor$TimedRunnable.run(OrderedExecutor.java:203) [org.apache.bookkeeper-bookkeeper-common-4.12.0.jar:4.12.0]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [io.netty-netty-common-4.1.60.Final.jar:4.1.60.Final]
	at java.lang.Thread.run(Thread.java:834) [?:?]

Modifications

Remove the error log stack.

Does this pull request potentially affect one of the following parts:

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• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (no)
• Anything that affects deployment: (no)

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