Fix the bug that canceled MPP query may cause tasks hang forever when…

… local tunnel is enabled. (#4219) (#4236)

close #4229

dbms/src/Flash/Mpp/MPPTask.cpp

@@ -352,6 +352,7 @@ void MPPTask::runImpl()
     }
     else
     {
+        context.getProcessList().sendCancelToQuery(context.getCurrentQueryId(), context.getClientInfo().current_user, true);
         writeErrToAllTunnels(err_msg);
     }
     LOG_INFO(log, "task ends, time cost is " << std::to_string(stopwatch.elapsedMilliseconds()) << " ms.");