avoid destroy() w/ lock

src/server/responseHandlers.cpp

@@ -2043,12 +2043,13 @@ void ServerMonitorRequesterImpl::destroy()
         // asCheck
         _channel->getChannelSecuritySession()->release(_ioid);
 
-        if (_channelMonitor)
-        {
-            _channelMonitor->destroy();
+        if (_channelMonitor) {
             _channelMonitor.reset();
         }
     }
+    if(monitor) {
+        monitor->destroy();
+    }
 }
 
 Monitor::shared_pointer ServerMonitorRequesterImpl::getChannelMonitor()