Bug#1106186: Merge request adding conflicts tag

[David Mandelberg]

Could you please leave it possible to install both systemd-resolved and 
unbound? They can do very different things, and I use both on the same 
system. systemd-resolved for the local forwarding resolver, and unbound 
on a different port to resolve DNS lists for spam checking since that 
can't go through a shared resolver like all other DNS traffic.