Fix issue with Namespace suffix on Gateway UI

There was a case where a deployment with a single namespace on
faas-netes would show the namespace suffix for all functions.  we didn't
need to show this because the gateway will proxy to the default
namespace for fns without the namespace siffix.

This was tested on Swarm (no suffix), faas-netes (single namespace, no
suffix) and faas-netes, multi-ns, suffix shown.

Signed-off-by: Alistair Hey <alistair@heyal.co.uk>

gateway/assets/index.html

@@ -140,7 +140,7 @@
                                 </md-input-container>
                                 <md-input-container class="md-block function-url" flex-gt-sm>
                                     <label>URL</label>
-                                    <input ng-value="(function.namespace && function.namespace.length > 0)? baseUrl + 'function/' + function.name + '.' + function.namespace : baseUrl + 'function/' + function.name" type="text" readonly="readonly">
+                                    <input ng-value="(function.namespace && function.namespace.length > 0 && allNamespaces && allNamespaces.length > 1)? baseUrl + 'function/' + function.name + '.' + function.namespace : baseUrl + 'function/' + function.name" type="text" readonly="readonly">
                                     <md-icon ng-if="canCopyToClipboard" md-svg-src="img/icons/outline-file_copy-24px.svg" ng-click="copyClicked($event)"></md-icon>
                                 </md-input-container>
                             </div>