fix reverse reference to user bookwyrm_groups

bookwyrm/templates/user/user.html

@@ -22,6 +22,9 @@
 
 {% block panel %}
 {% if user.bookwyrm_user %}
+{% for group in user.bookwyrm_groups.all %}
+<div>{{ group.name }}</div>
+{% endfor %}
 <div class="block">
     <h2 class="title">
         {% include 'user/shelf/books_header.html' %}