basic-system/network: Ensure dbus is really available for hostnamectl

Installing `dbus` does not start the service, even though it is enabled through
a symlink in /lib/systemd/system/sockets.target.wants.

basic-system/tasks/network.yml

 ---
-# file: roles/common/tasks/dns.yml
 
 - name: ensure dns is configured
   template:
@@ -19,6 +18,14 @@
     - dns
     - network
 
+- name: ensure dbus is really available
+  systemd:
+    name: dbus.socket
+    state: started
+  tags:
+    - dns
+    - network
+
 - name: ensure the hostname is not a fqdn
   hostname:
     name: "{{ ansible_hostname }}"