Azure Plugin: fix template when plugin is disabled - refs BT#9859

plugin/azure_active_directory/view/block.tpl

@@ -4,9 +4,11 @@
             <h4>{{ azure_active_directory.block_title }}</h4>
         {% endif %}
 
-        <a href="{{ azure_active_directory.signin_url }}" class="btn btn-default">{{ 'SignIn'|get_lang }}</a>
+        {% if not azure_active_directory.signin_url is empty %}
+            <a href="{{ azure_active_directory.signin_url }}" class="btn btn-default">{{ 'SignIn'|get_lang }}</a>
+        {% endif %}
 
-        {% if azure_active_directory.signout_url is not empty %}
+        {% if not azure_active_directory.signout_url is empty %}
             <a href="{{ azure_active_directory.signout_url }}" class="btn btn-danger">{{ 'Logout'|get_lang }}</a>
         {% endif %}
     </div>