File mp-5.62-qt6-isnull.patch of Package mp

fix test that still worked in Qt5 but does not in Qt6

--- a/mpv_qk_common.cpp	2024-12-07 08:52:47.000000000 +0100
+++ b/mpv_qk_common.cpp	2025-05-26 10:39:15.220655492 +0200
@@ -70,7 +70,7 @@
 {
     mpdm_t r = NULL;
 
-    if (s != NULL) {
+    if (!s.isNull()) {
         int t = s.size();
         wchar_t *wptr = (wchar_t *) calloc((t + 1), sizeof(wchar_t));