Show errors on delete view

gas/templates/gas/delete_confirmation.html

@@ -1,10 +1,12 @@
 {% extends base_template %}
 
 {% load i18n %}
+{% load form_tags %}
 
 {% block ui_title %}{% trans "Delete confirmation" %}{% endblock %}
 
 {% block content %}
+    {% form_errors form %}
     <p>{{ confirmation_text }}</p>
 
     {% if show_deleted_objects %}