Prevent duplicated lines

In case where /etc/network/interfaces already contains a similar
line, it is superseeded.

Change-Id: I38f244d093e002f8bc90412c1eacd254ffe31514
(cherry picked from commit 42d14389b0)

multi-node-aio/playbooks/setup-host.yml

@@ -132,6 +132,7 @@
       lineinfile:
         line: "source /etc/network/interfaces.d/*.cfg"
         dest: "/etc/network/interfaces"
+        regexp: "^source /etc/network/interfaces.d/.*"
 
     - name: Set the host intefaces up
       command: "/sbin/ifup {{ item.value.iface }}"