fix typo

src/Resources/views/Admin/UiElement/button.html.twig

@@ -9,7 +9,7 @@
 #}
 {% set align = element.align is defined and element.align is not empty ? element.align : 'center' %}
 {% set target = element.target is defined and element.target is not empty ? element.target : '_self' %}
-{% set rel = element.target is defined and element.target == '_blank' ? 'rel="noopener noreferrer"' : '' }
+{% set rel = element.target is defined and element.target == '_blank' ? 'rel="noopener noreferrer"' : '' %}
 
 <p style="text-align: {{align}};">
     <a href="{{ element.link }}" target="{{ element.target }}" {{ rel }} class="ui primary button massive">{{ element.label }}</a>