Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  908c93f0d7dba13a022f755e8cde2c1e6be5643a

Hygiene: Manage z-index with less variables

Defined 5 standard z-index layers (to be revisited
later)

Bug: 64707
Change-Id: I2b22ed53650e688f80e520db84305ab60c2e4782