conversations: fix recipient search pagination

fixes CNVS-10209

test plan:
  * open old conversations
  * in the recipient search, select a course with more than ten people
  * scroll to the bottom
  * confirm that all of the people in the course are present

Regression appears to have been introduced in
https://gerrit.instructure.com/26489 .

Change-Id: Ie2bb7cf3d6c348ae753fc245d719dfb081948ea2
Reviewed-on: https://gerrit.instructure.com/28016
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Zach Pendleton <zachp@instructure.com>
Product-Review: Zach Pendleton <zachp@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>

Author: bluej100

app/coffeescripts/widget/TokenSelectorList.coffee

@@ -49,14 +49,14 @@ define [
       91: 'Command'
 
     initialize: (options) ->
+      @paginationScrollContainer = $('<ul />', role: 'menu')
       super
       @selector = @options.selector
       @parent = @options.parent
       @ancestors = @options.ancestors
       @query = @options.query
 
       @$heading                  = $('<ul />', class: 'heading').appendTo(@$el)
-      @paginationScrollContainer = $('<ul />', role: 'menu')
       @$body                     = @paginationScrollContainer.appendTo(@$el)
 
       @$el.find('ul')