Fixes focus not being set on gamelist after tab change

Once a tab is selected the focus can be set directly from the page
changed event. However once the tab was shown, the first tab order
control element was given the focus by default. This was fixed by
delaying the action and setting the focus after the default focus
had been assigned.

Source/Core/DolphinWX/NetPlay/NetPlaySetupFrame.h

@@ -38,6 +38,8 @@ private:
   void OnResetTraversal(wxCommandEvent& event);
   void OnTraversalListenPortChanged(wxCommandEvent& event);
   void OnKeyDown(wxKeyEvent& event);
+  void OnTabChanged(wxCommandEvent& event);
+  void OnAfterTabChange(wxIdleEvent& event);
   void DispatchFocus();
 
   void MakeNetPlayDiag(int port, const std::string& game, bool is_hosting);