Fix memory leak in wxTextCtrl au_check_word that was triggered only with wxTE_AUTO_URL style

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@46512 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/textctrl.cpp

@@ -424,7 +424,7 @@ au_check_word( GtkTextIter *s, GtkTextIter *e )
     gtk_text_iter_backward_find_char( &end, pred_nonpunct_or_slash, NULL, &start );
     gtk_text_iter_forward_char(&end);
 
-    gchar* text = gtk_text_iter_get_text( &start, &end );
+    wxGtkString text(gtk_text_iter_get_text( &start, &end ));
     size_t len = strlen(text), prefix_len;
     size_t n;