dont try set maxmemory_policy if setting does not exist

[p1u3o]

Apache KVRocks supports the needed Redis commands (see https://kvrocks.apache.org/docs/supported-commands) to be a backend for JuiceFS, however because it uses RocksDB, there is no max_memory policy, but JuiceFS will try and set this, resulting in an non-critical error at startup.

[CLAassistant]

All committers have signed the CLA.

[zhijian-pro]

Replacing

juicefs/pkg/meta/redis.go

Line 3551 in 7d660d9

if rInfo.storageProvider == "" && rInfo.maxMemoryPolicy != "noeviction" {

with

if rInfo.storageProvider == "" && rInfo.maxMemoryPolicy != "" && rInfo.maxMemoryPolicy != "noeviction" {

is logically simpler

[p1u3o]

I agree, I'll change this MR.

[p1u3o]

I have updated this MR with the suggested change and confirmed it works at silencing the error.