add markup to topics list view

views/user/settings.etlua

@@ -1,3 +1,4 @@
+<% local disable_avatar = me:is_logged_in_guest() %>
 <div class="darkbg settings-container">
   <h1>User settings</h1>
   <% if infobox then %>
@@ -7,7 +8,7 @@
     <img src="<%= avatar_url(me) %>">
     <input id="file" type="file" name="avatar" accept="image/*" required>
     <div>
-    <input type="submit" value="Update avatar">
+    <input type="submit" value="Update avatar" <%= disable_avatar and "disabled=disabled" %>>
   <% if not me:is_default_avatar() then %>
     <input type="submit" value="Clear avatar" formaction="<%= url_for("user_clear_avatar", {username = me.username}) %>" formnovalidate>
   <% end %>