Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  50fa4cfd6e86ed45569e207d87cc8a696cae6475

Update pre-commit hook to use optipng+advdef not pngcrush

optipng -o7 "$png" && advpng -z -4 "$png" && advdef -z -4 "$png"

Change-Id: Ic02b8fb8cdd79a861b76143d42de2d484ed72e56