Improve reporting of assert in IndexShard

Conflicts:
	src/main/java/org/elasticsearch/index/shard/IndexShard.java

Author: s1monw

src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -220,7 +220,7 @@ public IndexShard(ShardId shardId, @IndexSettings Settings indexSettings, IndexS
         this.codecService = codecService;
         this.shardSuggestService = shardSuggestService;
         this.shardFixedBitSetFilterCache = shardFixedBitSetFilterCache;
-        assert clusterService.lifecycleState() == Lifecycle.State.STARTED; // otherwise localNode is still none;
+        assert clusterService.lifecycleState() == Lifecycle.State.STARTED : "expected lifecycle to be started but was: " + clusterService.lifecycleState() ; // otherwise localNode is still none;
         this.localNode = clusterService.localNode();
         state = IndexShardState.CREATED;
         this.refreshInterval = indexSettings.getAsTime(INDEX_REFRESH_INTERVAL, EngineConfig.DEFAULT_REFRESH_INTERVAL);