QmlProfiler: Stop run control if connection to external app closes

We don't have control over the application's life cycle in this case, so
we need to use the debug connection as indicator.

Change-Id: I3f30194e12c10c6585a58133c5148dbea9e6761f
Task-number: QTCREATORBUG-19496
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmlprofiler/qmlprofilertool.cpp

@@ -562,6 +562,8 @@ void QmlProfilerTool::attachToWaitingApplication()
     auto profiler = new QmlProfilerRunner(runControl);
     profiler->setServerUrl(serverUrl);
 
+    connect(d->m_profilerConnections, &QmlProfilerClientManager::connectionClosed,
+            runControl, &RunControl::initiateStop);
     ProjectExplorerPlugin::startRunControl(runControl);
 }