Revert "Update MVK again to fix avcodec compilation"

This reverts commit c07daf14ee007ea508668263746a4835c7388844.

compileVLCforiOS.sh

@@ -12,7 +12,7 @@ CONFIGURATION="Release"
 NONETWORK=no
 SKIPLIBVLCCOMPILATION=no
 
-TESTEDVLCKITHASH=7e648920b
+TESTEDVLCKITHASH=42c0ae224
 TESTEDMEDIALIBRARYKITHASH=9c6382eb1
 
 usage()