Removing extraneous render from team_discussion.js

On the advice of https://github.com/edx/edx-platform/pull/9470,
the render call here is not needed and should be removed in order
to allow the view's owner to determine when it needs to be rendered.

This will hopefully also fix the flaky tests we've been seeing,
we'll need to continue to monitor the builds to be sure.

lms/djangoapps/teams/static/teams/js/views/team_discussion.js

@@ -8,7 +8,6 @@
             var TeamDiscussionView = Backbone.View.extend({
                 initialize: function () {
                     window.$$course_id = this.$el.data("course-id");
-                    this.render();
                 },
 
                 render: function () {