Debugger: Do not enable QML-debugging by default for projects using C++.

QML-debugging is rarely desired for C++ projects and causes warnings
about timeouts from the QML debugger not being able to connect.

Change-Id: Ide3e870a40b49deae24d3d88ea4973dd45d83e75
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/debuggerrunconfigurationaspect.cpp

@@ -226,9 +226,11 @@ bool DebuggerRunConfigurationAspect::useCppDebugger() const
 
 bool DebuggerRunConfigurationAspect::useQmlDebugger() const
 {
-    if (m_useQmlDebugger == DebuggerRunConfigurationAspect::AutoEnabledLanguage)
-        return runConfiguration()->target()->project()->projectLanguages().contains(
-                    ProjectExplorer::Constants::LANG_QMLJS);
+    if (m_useQmlDebugger == DebuggerRunConfigurationAspect::AutoEnabledLanguage) {
+        const Core::Context languages = runConfiguration()->target()->project()->projectLanguages();
+        return languages.contains(ProjectExplorer::Constants::LANG_QMLJS)
+            && !languages.contains(ProjectExplorer::Constants::LANG_CXX);
+    }
     return m_useQmlDebugger == DebuggerRunConfigurationAspect::EnabledLanguage;
 }