Remove "Help/Project" profile from Special:Search

The vast majority of wikis have an empty help namespace and
searching project pages is mostly an advanced search feature.

Cluttering the UI with an extra tab that's (most likely) rarely
clicked isn't helping anyone.

Change-Id: I0c448bcee877e027ff95c96812aac86d89d4eb32
Merge "Remove "Help/Project" profile from Special:Search"