ui: hide register floatbox if not allowed to register

packages/ui-default/templates/partials/login_dialog.html

@@ -1,13 +1,11 @@
 <div class="dialog dialog--signin" style="display:none">
   <div class="dialog__content">
-    {% if model.system.get('server.login') %}
+    {% if model.system.get('server.login') and handler.user.hasPriv(PRIV.PRIV_REGISTER_USER) %}
     <div class="dialog--signin__bg">
       <div class="dialog--signin__side">
         <h1>{{ _("Don't have an account?") }}</h1>
         <p>{{ _('By signing up a {0} universal account, you can submit code and join discussions in all online judging services provided by us.').format((handler.domain|default({ui:[]})).ui.name|default(model.system.get('server.name'))) }}</p>
-        {% if handler.user.hasPriv(PRIV.PRIV_REGISTER_USER) %}
         <div><a href="{{ url('user_register') }}" class="inverse rounded button">{{ _('Sign Up Now') }}</a></div>
-        {% endif %}
       </div>
     </div>
     {% endif %}