[packages] avahi: remove inappropriate dependency on dbus in Changeset 32330

[packages] avahi: remove inappropriate dependency on dbus in Changeset 32330

This patch fixes an issue reported by Damiano Albani.
Changeset 32330, while fixing one bug, unfortunately introduces another one -- it makes
avahi-daemon always dependent on the dbus package, causing dbus to be
loaded even when it's not needed.

This patch makes avahi-daemon dependent on dbus only is avahi dbus support has been selected.

Signed-off-by Mike Brady <mikebrady@eircom.net>

SVN-Revision: 33267