[CP] change sync rpc to async for transfer and migration

src/share/ob_debug_sync_point.h

@@ -558,6 +558,7 @@ class ObString;
     ACT(BEFORE_CHECK_PRIMARY_ZONE,)\
     ACT(BEFORE_RELOAD_UNIT,)\
     ACT(BEFORE_PROCESS_EVENT_TASK,)\
+    ACT(BEFORE_CHECK_LS_TRANSFER_SCN_FOR_STANDBY,)\
     ACT(MAX_DEBUG_SYNC_POINT,)
 
 DECLARE_ENUM(ObDebugSyncPoint, debug_sync_point, OB_DEBUG_SYNC_POINT_DEF);