Hygiene: Correct the hook parameter

This hook provides a Skin object not a Title object
See:
https://www.mediawiki.org/wiki/Manual:Hooks/SkinTemplateOutputPageBeforeExec
if you don't believe me ;-)

Change-Id: I31cf5f8cdf85cc26d5da40d2dd6fb38b64dd02ac
Merge "Hygiene: Correct the hook parameter"