gitblit: use apache::site

fix apache site setup on git.wm.org

currently on antimony the git.wm.org config cant't
be changed anymore, because:

git.wikimedia.org]: Ensure set to :present but file type is link so no content will be synced

unsure when it started, but:

* use apache::site resource
* alphabetize includes and add them to top
* remove unneeded webserver::apache include

to fix the issue

Change-Id: Ie5af5e55a11a9d1c3de203bf7176395a3890c3ea