tag-detail.html: Fix shown docker pull command

when image has no `repositoryUser`.

Author: msabramo

app/tag/tag-detail.html

@@ -27,7 +27,7 @@ <h1>
 </h1>
 
 <div class="well">
-  docker pull {{registryHost.host}}<span ng-if="registryHost.port != 80 && registryHost.port != 443">:{{registryHost.port}}</span>/{{repositoryUser}}/{{repositoryName}}:{{tagName}}
+  docker pull {{registryHost.host}}<span ng-if="registryHost.port != 80 && registryHost.port != 443">:{{registryHost.port}}</span>/{{repository}}:{{tagName}}
 </div>
 
 <image-details></image-details>