Qt4Project: Don't update runconfigurations for all targets

Change-Id: I383d0c5b7f01bf00be3249dc2721e69ed27dc148
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/qt4projectmanager/qt4project.cpp

@@ -685,8 +685,8 @@ void Qt4Project::update()
 
 void Qt4Project::updateRunConfigurations()
 {
-    foreach (Target *t, targets())
-        t->updateDefaultRunConfigurations();
+    if (activeTarget())
+        activeTarget()->updateDefaultRunConfigurations();
 }
 
 void Qt4Project::scheduleAsyncUpdate(Qt4ProFileNode *node)