Only run mediawiki_reload provisioner if trigger exists
Only run mediawiki_reload provisioner if trigger exists

The provisioner itself checks for the presence of a TRIGGER file, but checking
in Vagrantfile spares us the 'Running provisioner mediawiki_reload...' line on
each invocation of 'vagrant provision'.

Change-Id: I8e2a293fce1df45e2d0b6384019d70cee1e6df85

HarriAlasi/wiki3dviewer,ankita-kumari/mediawiki-vagrant,stuartbman/mediawiki-vagrant,wikimedia/mediawiki-vagrant,HarriAlasi/wiki3dviewer,stuartbman/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,HarriAlasi/wiki3dviewer,ankita-kumari/mediawiki-vagrant,wikimedia/mediawiki-vagrant,HarriAlasi/wiki3dviewer,HarriAlasi/wiki3dviewer,wikimedia/mediawiki-vagrant,stuartbman/mediawiki-vagrant,stuartbman/mediawiki-vagrant,stuartbman/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,HarriAlasi/wiki3dviewer,stuartbman/mediawiki-vagrant,HarriAlasi/wiki3dviewer,stuartbman/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant