[FIX] Use proper HTML5 tags instead of self-closing XML/XHTML tags

allianceauth/fleetactivitytracking/templates/fleetactivitytracking/fatlinkformatter.html

@@ -21,7 +21,7 @@
                         <form class="form-signin" role="form" action="" method="POST">
                             {% csrf_token %}
                             {{ form|bootstrap }}
-                            <br/>
+                            <br>
                             <button class="btn btn-lg btn-primary btn-block" type="submit" name="submit_fat">{% translate "Create fatlink" %}</button>
                         </form>
                 </div>