httpsession: cancel other activities when closing

This fixes a possible assert after failing to apply filters in tryProcessOutReq. When filtering fails, the state is set to Closing but the outbound request is left alive, and any activity from the outbound request while in that state is unexpected behavior. In general, we don't want concurrent operations going on while we are closing, so to avoid this problem and potentially similar problems we'll ensure other activities are canceled first.

src/handler/httpsession.cpp

@@ -571,6 +571,9 @@ class HttpSession::Private : public QObject
 
 	void prepareToClose()
 	{
+		cleanupOutReq();
+		cleanupAction();
+
 		state = Closing;
 
 		publishQueue.clear();