Remove last use of silk icons in twig layout.

When we remove old templates we can also remove silk.

modules/core/templates/frontpage_config.twig

@@ -9,8 +9,8 @@
         <code class="simplesaml_version">{{ directory }} ({{ version }})</code>
     </div>
 
-    {% set icon_enabled = '<img src="/' ~ baseurlpath ~ 'resources/icons/silk/accept.png" alt="enabled" />' %}
-    {% set icon_disabled = '<img src="/' ~ baseurlpath ~ 'resources/icons/silk/delete.png" alt="disabled" />' %}
+    {% set icon_enabled = '<i class="fa fa-check"></i>' %}
+    {% set icon_disabled = '<i class="fa fa-ban"></i>' %}
 
     <div class="enablebox mini">
         <table>

templates/index.twig

@@ -12,10 +12,10 @@
             <table>
 
                 <tr class="disabled"><td>SAML 2.0 IdP</td>
-                    <td><img src="/{{ baseurlpath }}resources/icons/silk/delete.png" alt="disabled" /></td></tr>
+                    <td><i class="fa fa-ban"></i></td></tr>
 
                 <tr class="disabled"><td>Shib 1.3 IdP</td>
-                    <td><img src="/{{ baseurlpath }}resources/icons/silk/delete.png" alt="disabled" /></td></tr>
+                    <td><i class="fa fa-ban"></i></td></tr>
 
             </table>
         </div>