Fixes plugin.ini error

When executing the cisco.pp manifest it throws an error
if the plugin.ini file is already declared.

Change-Id: Ibc9c8d343d86ffa8af74767ac6fbbd75cf03f45c

manifests/plugins/cisco.pp

@@ -171,9 +171,14 @@
 
   # In RH, this link is used to start Neutron process but in Debian, it's used only
   # to manage database synchronization.
-  ensure_resource('file', '/etc/neutron/plugin.ini', {
-    ensure  => link,
-    target  => '/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini',
-    require => Package['neutron-plugin-ovs']
-  })
+  if defined(File['/etc/neutron/plugin.ini']) {
+    File <| path == '/etc/neutron/plugin.ini' |> { target => '/etc/neutron/plugins/cisco/cisco_plugins.ini' }
+  }
+  else {
+    file {'/etc/neutron/plugin.ini':
+      ensure  => link,
+      target  => '/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini',
+      require => Package['neutron-plugin-ovs'],
+    }
+  }
 }