show default title if no custom one was specified instead of clearing it (patch 1829254)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@49803 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/colordlg.cpp

@@ -69,7 +69,9 @@ wxColourDialogHookProc(HWND hwnd,
         CHOOSECOLOR *pCC = (CHOOSECOLOR *)lParam;
         wxColourDialog *dialog = (wxColourDialog *)pCC->lCustData;
 
-        ::SetWindowText(hwnd, dialog->GetTitle());
+        const wxString& title = dialog->GetTitle();
+        if ( !title.empty() )
+            ::SetWindowText(hwnd, title);
 
         wxPoint pos = dialog->GetPosition();
         if ( pos != wxDefaultPosition )