Update MVK to fix playback and thumbnails

compileVLCforiOS.sh

@@ -12,7 +12,7 @@ CONFIGURATION="Release"
 NONETWORK=no
 SKIPLIBVLCCOMPILATION=no
 
-TESTEDVLCKITHASH=0927257a
+TESTEDVLCKITHASH=8ff9e574
 TESTEDMEDIALIBRARYKITHASH=e5ca039f
 
 usage()