add bareos-webui-php-fpm-to-director docker network rockstor#94

It appears that we need this network in order that the PHP
code this container carries can also resolve our director.
We have a current limitation regarding unique `source_container`
network config entries, which prevents us from simply having
`bareos-webui-php-fpm` as an additional source_container entry
in the "bareos-director" network. This was encountered when adding
the bareos-webui network.

bareos-server-set.json

@@ -23,6 +23,12 @@
           "name": "bareos-webui-to-webui-php-fpm",
           "source_container": "bareos-webui-php-fpm"
         }
+      ],
+      "bareos-webui-php-fpm": [
+        {
+          "name": "bareos-webui-php-fpm-to-director",
+          "source_container": "bareos-director"
+        }
       ]
     },
     "containers": {