Use simpler Plugin::initialize() when feasible

Change-Id: I567965d266f20526bda9f823e31a04b354d53fb1
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/qmlprojectmanager/qmlprojectplugin.h

@@ -36,7 +36,7 @@ public slots:
     void openQds(bool permanent = false);
 
 private:
-    bool initialize(const QStringList &arguments, QString *errorString) final;
+    void initialize() final;
     void displayQmlLandingPage();
     void hideQmlLandingPage();
     void updateQmlLandingPageProjectInfo(const Utils::FilePath &projectFile);