Recommend dnsmasq-base instead of dnsmasq

this keeps us out of all the dnsmasq already running troubles.

Closes: #516443
Thanks: Bin Zhang for the suggestion and the doc update

debian/README.Debian

@@ -37,8 +37,10 @@ To make the default network start automatically use:
  virsh net-autostart default
 
 In order for things to work this way you need to have the recommended packages
-dnsmasq, bridge-utils and iptables installed. However Debian's default dnsmasq
-needs to be adjusted slightly to interoperate with libvirtd:
+dnsmasq-base, bridge-utils and iptables installed.
+
+You don't need the package dnsmasq. However, if you install it, Debian's
+default dnsmasq needs to be adjusted slightly to interoperate with libvirtd:
 
 cat <<EOF >/etc/dnsmasq.d/00_libvirtd.conf
 # only bind to loopback by default

debian/control

@@ -15,7 +15,7 @@ Architecture: any
 Depends: ${shlibs:Depends}, ${misc:Depends}, adduser, libvirt0 (>= ${binary:Version}), logrotate
 Enhances: qemu, kvm, xen
 Section: admin
-Recommends: netcat-openbsd, bridge-utils, dnsmasq (>= 2.46-1), iptables, qemu (>= 0.9.1)
+Recommends: netcat-openbsd, bridge-utils, dnsmasq-base (>= 2.46-1), iptables, qemu (>= 0.9.1)
 Suggests: policykit
 Description: the programs for the libvirt library
  Libvirt is a C toolkit to interact with the virtualization capabilities