Fix wrongly try to rewrite the namespace in the cluster mode

[git-hulk]

This closes #2214

The namespace mechanism is NOT allowed in cluster mode, so it's
unnecessary to rewrite while the cluster mode is enabled. This
config rewrite behavior will cause the replication issue which was
mentioned in #2214 when starting the cluster node.

The root cause is that the server will try to rewrite the namespace
into the rocksdb if the option repl-namespace-enabled is enabled.
So it will increase the server's rocksdb sequence and replication will
start with the wrong offset. We have checked if the role is a slave
before rewriting, but the cluster replication is NOT set at that time(master-replica is good).

The good news is it only affects the cluster users who enabled
the option repl-namespace-enabled, so I guess almost no user
will do this since the namespace replication is meaningless to the cluster mode.

Please refer to the first commit in this PR for the reproduced code.
The replica will lose one update before applying this patch:

=== RUN   TestClusterReplication/Cluster_replication_should_work_normally_after_restart
    replication_test.go:88: 
        	Error Trace:	/Users/hulk/code/cxx/kvrocks/tests/gocase/integration/replication/replication_test.go:88
        	Error:      	Not equal: 
        	            	expected: "v1"
        	            	actual  : "v0"

And it works well after this patch.

[torwig]

LGTM

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
62.9% Coverage on New Code
5.0% Duplication on New Code

See analysis details on SonarCloud