Fix JS comment deletion

If the comment tree had just one top level comment the whole tree was
removed by the JS code if just one comment in the tree was deleted.
These comments were (correctly) not removed from the ZODB.

CHANGES.txt

@@ -4,6 +4,9 @@ Changelog
 2.1.6 (unreleased)
 ------------------
 
+- Fix excessive JS comment deletion.
+  [gaudenz]
+
 - No longer depend on zope.app packages.
   [hannosch]
 

plone/app/discussion/browser/javascripts/comments.js

@@ -179,12 +179,6 @@
                 url: form_url,
                 context: $(trigger).parents(".comment"),
                 success: function (data) {
-                    if ($(".discussion .replyTreeLevel0").length === 1) {
-                        $(".discussion").fadeOut('fast', function () {
-                            $(".discussion").remove();
-                        });
-                    }
-                    else {
                     var comment = $(this);
                     var clss = comment.attr('class');
                     // remove replies
@@ -203,7 +197,6 @@
                     $(this).fadeOut('fast', function () {
                         $(this).remove();
                     });
-                    }
                 },
                 error: function (req, error) {
                     return true;