fix use of stack variable after it has gone out of scope, closes #16423

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77082 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/window.cpp

@@ -1552,6 +1552,7 @@ static void SendSetCursorEvent(wxWindowGTK* win, int x, int y)
         {
             gs_overrideCursor = &event.GetCursor();
             win->GTKUpdateCursor();
+            gs_overrideCursor = NULL;
             gs_needCursorResetMap[win] = true;
             return;
         }