[accounts][templates] hide supervision management if no supervisee

beat/web/accounts/templates/accounts/settings.html

@@ -324,6 +324,7 @@
           <hr />
           {% endif %}
 
+          {% if supervisiontracks_valid|length > 0 %}
           <li class="list-group-item" style="text-align:center;"><b>Supervision list</b></li>
           <table class="table">
             <thead>
@@ -361,6 +362,7 @@
 
           <li class="list-group-item"><i>Valid supervisees are marked in green and supervisees that are under a revalidation process (yearly basis) are marked in yellow.
 You can remind them to revalidate there account before the expiration date or else their account will get blocked (and need to pass through an unblock procedure)</i><br>
+         {% endif %}
           </div>
         </form>
       </div>