[FIX] BG color classes

Use `text-bg-*` instead of just `bg-*` to make use of Bootstraps native text color selection for those backgrounds.

allianceauth/services/modules/discourse/templates/services/discourse/discourse_service_ctrl.html

@@ -14,7 +14,7 @@
 {% endblock %}
 
 {% block active %}
-    <span class="badge bg-success">
+    <span class="badge text-bg-success">
         {% translate "SSO login active" %}
     </span>
 {% endblock %}