Remove changeEvent(QEvent::LanguageChange) implementation

This was implemented only for a small set of widgets. It's unlikely that
we will ever have or even want a dynamic language selection, until then
this code is only dead freight.

Change-Id: I1bff4e1e89057786c0e5cb57225a508c5d390d9c
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/mercurial/revertdialog.h

@@ -47,9 +47,6 @@ public:
 
     QString revision() const;
 
-protected:
-    void changeEvent(QEvent *e);
-
 private:
     Ui::RevertDialog *m_ui;
 };