Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  0aa6c2cbf18c500ea55a7eef495efefa16a083ac

Story 1402: A/B test showing edit guider after user creates an account

Also introduce M.isBetaGroupMember

Change-Id: I996d2872a948d870eb6d0cd74b9c2c6e010e52aa