Fix some styles.

lms/static/coffee/src/discussion/views/discussion_thread_view.coffee

@@ -19,7 +19,7 @@ class @DiscussionThreadView extends Backbone.View
     if window.user.voted(@model)
       @$(".vote-btn").addClass("is-cast")
     @$("span.timeago").timeago()
-    DiscussionUtil.makeWmdEditor @$el, $.proxy(@$, @), "reply-body"
+    Markdown.makeWmdEditor @$(".reply-body"), "", DiscussionUtil.urlFor("upload"), (text) -> DiscussionUtil.postMathJaxProcessor(text)
     @renderResponses()
     @