hot fix: Updated variable names & comments (#461)

- Fixed a wrong condition on the users subscribing history `read` permission.
- The comments are clearer and mentions how to specify clubs by their id.

core/templates/core/user_detail.jinja

@@ -145,7 +145,7 @@
         {% endif %}
         </div>
     {% endif %}
-    {% if profile.was_subscribed and (user == profile or user.is_root or user.is_board_member or user.can_read_subscription)%}
+    {% if profile.was_subscribed and (user == profile or user.can_read_subscription_history)%}
         <div id="drop_subscriptions">
             <h5>{% trans %}Subscription history{% endtrans %}</h5>
             <table>