`grunt-contrib-imagemin` was updated, which included some changes to image minification. Those changes are now applies. Props netweb. See #45080. Built from https://develop.svn.wordpress.org/branches/5.0@43785 git-svn-id: http://core.svn.wordpress.org/branches/5.0@43614 1a063a9b-81f0-0310-95a4-ce76da25c4cd