Make sure subscribers are enabled before displaying add subscriber

resources/views/dashboard/subscribers/index.blade.php

@@ -8,7 +8,7 @@
     <span class="uppercase">
         <i class="ion ion-ios-email-outline"></i> {{ trans('dashboard.subscribers.subscribers') }}
     </span>
-    @if($current_user->isAdmin)
+    @if($current_user->isAdmin && subscribes_enabled())
     <a class="btn btn-sm btn-success pull-right" href="{{ route('dashboard.subscribers.add') }}">
         {{ trans('dashboard.subscribers.add.title') }}
     </a>