App: Retranslate all pages when the language is changed

launcher/ui/pages/modplatform/VanillaPage.h

@@ -52,6 +52,8 @@ public:
         return "Vanilla-platform";
     }
     virtual bool shouldDisplay() const override;
+    void retranslate() override;
+
     void openedImpl() override;
 
     BaseVersionPtr selectedVersion() const;