Bug#913823: apache2: dav.load does not check for an already loaded dav_module

[Nye Liu <nyet@nyet.org>]

Package: apache2
Version: 2.4.38-1
Followup-For: Bug #913823

Workaround in /etc/apache2/mods-available/dav.load:

<IfModule !mod_dav.c>
    LoadModule dav_module /usr/lib/apache2/modules/mod_dav.so
</IfModule>

Alternately just make dav_fs not depend on dav, it will autoload it.