Stop conditionally registering oojs and oojs-ui

We already have wfUseMW( '1.24wmf6' ) so we don't need this any more.

The messages list for oojs-ui had gotten out of date, and rather than
fixing it I figured we should just remove this conditional registration
code altogether.

Change-Id: If0610beb2df8bd85aeba136530a84a793e3dda64
Merge "Stop conditionally registering oojs and oojs-ui"