HBASE-22601 Misconfigured addition of peers leads to cluster shutdown. (#500)

Signed-off-by: Duo Zhang <zhangduo@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSource.java

@@ -511,6 +511,10 @@ public class ReplicationSource implements ReplicationSourceInterface {
       }
     }
 
+    if (!this.isSourceActive()) {
+      return;
+    }
+
     // In rare case, zookeeper setting may be messed up. That leads to the incorrect
     // peerClusterId value, which is the same as the source clusterId
     if (clusterId.equals(peerClusterId) && !replicationEndpoint.canReplicateToSameCluster()) {