refactor(sync): fix asan error

source/libs/sync/src/syncMain.c

@@ -1403,7 +1403,7 @@ void syncNodeDoConfigChange(SSyncNode* pSyncNode, SSyncCfg* pNewConfig, SyncInde
       // reset sender
       bool reset = false;
       for (int32_t j = 0; j < TSDB_MAX_REPLICA; ++j) {
-        if (syncUtilSameId(&(pSyncNode->replicasId)[i], &oldReplicasId[j])) {
+        if (syncUtilSameId(&(pSyncNode->replicasId)[i], &oldReplicasId[j]) && oldSenders[j] != NULL) {
           char     host[128];
           uint16_t port;
           syncUtilU642Addr((pSyncNode->replicasId)[i].addr, host, sizeof(host), &port);
@@ -1420,6 +1420,8 @@ void syncNodeDoConfigChange(SSyncNode* pSyncNode, SSyncCfg* pNewConfig, SyncInde
 
           sNTrace(pSyncNode, "snapshot sender udpate replicaIndex from %d to %d, %s:%d, %p, reset:%d", oldreplicaIndex,
                   i, host, port, (pSyncNode->senders)[i], reset);
+
+          break;
         }
       }
     }