Corrent setting name in the comment

Signed-off-by: Tianli Feng <[email protected]>

server/src/test/java/org/opensearch/cluster/coordination/NoMasterBlockServiceRenamedSettingTests.java

@@ -17,7 +17,7 @@
 import java.util.Set;
 
 /**
- * A unit test to validate the former name of the setting 'cluster.service.slow_cluster_manager_task_logging_threshold' still take effect,
+ * A unit test to validate the former name of the setting 'cluster.no_cluster_manager_block' still take effect,
  * after it is deprecated, so that the backwards compatibility is maintained.
  * The test can be removed along with removing support of the deprecated setting.
  */