Fix "Opening already running instance"

In src/gui/TrayIcon.qml the showUpWatcher looked for the settingsFolder
in the qrc file context so it didn't notice changes in the real settingsFolder.

Fixes #126

src/main.cpp

@@ -489,7 +489,7 @@ int main(int argc, char *argv[]) {
         app.exit(EXIT_FAILURE);
     }
 
-    component.create(objectContext)->setProperty("settingsFolder", settingsFolder);
+    component.create(objectContext)->setProperty("settingsFolder", "file://"+settingsFolder);
 
     // Finally, execute the app. Return its exit code after clearing the lock.
     int exit_code = app.exec();