Bug#718166: a2disconf fails on purge when conf already gone

["Jean-Michel Vourgère" <jmv_deb@nirgal.com>]

I spent "some" time on that issue, and could not find a reasonable aswner:

I noticed that dh_apache2 generates snipets with:
	apache2_invoke enconf phppgadmin || exit $?
Adding the "|| exit $?" really does help (I could not believe it at first).

This may somehow be linked to the fact that that apache2-maintscript-helper:415
calls that specific a2disconf in a subshell (see comment there).

Just my 2 cents... This is way too subtile for me.
I agree a2disconf --purge return code is surprising.