removed unused variable left after the last commit

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@47627 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/dirdlg.cpp

@@ -109,7 +109,6 @@ wxDirDialog::wxDirDialog(wxWindow* parent, const wxString& title,
             return;
         }
 
-        GtkFileChooserAction gtk_action;
         GtkWindow* gtk_parent = NULL;
         if (parent)
             gtk_parent = GTK_WINDOW( gtk_widget_get_toplevel(parent->m_widget) );