fix relative path for playback_url

refs COMMS-1163
fixes COMMS-1273

Test Plan:
- Tests Pass
- we will be verifying this on beta

Change-Id: I924e8ec4aec17873e1ce7855c55122dbbceeca01
Reviewed-on: https://gerrit.instructure.com/155940


Reviewed-by: Sara Chadwick <schadwick@instructure.com>
Tested-by: Jenkins
Product-Review: Steven Burnett <sburnett@instructure.com>
QA-Review: Steven Burnett <sburnett@instructure.com>

app/views/jst/conferences/concludedConference.handlebars

@@ -67,7 +67,7 @@
               <div class="ig-info">
                 <div class="ig-details">
                   {{#if ../../isAdobeConnect}}
-                    <a id="adobe-connect-playback-link" href="{{../../playback_url}}" target="_blank" class="ig-title"
+                    <a id="adobe-connect-playback-link" href="{{../playback_url}}" target="_blank" class="ig-title"
                       style="line-height: inherit;" data-id="{{../../recording_id}}" data-format="presentation">
                       {{title}}
                     </a>

app/views/jst/conferences/newConference.handlebars

@@ -100,7 +100,7 @@
               <div class="ig-info">
                 <div class="ig-details">
                   {{#if ../../isAdobeConnect}}
-                    <a id="adobe-connect-playback-link" href="{{../../playback_url}}" target="_blank" class="ig-title"
+                    <a id="adobe-connect-playback-link" href="{{../playback_url}}" target="_blank" class="ig-title"
                       style="line-height: inherit;" data-id="{{../recording_id}}" data-format="presentation">
                       {{title}}
                     </a>

spec/coffeescripts/views/conferences/ConferenceViewSpec.js

@@ -36,7 +36,6 @@ const conferenceView = function(conferenceOpts = {}) {
     context_code: 'course_1',
     context_id: 1,
     context_type: 'Course',
-    playback_url: 'www.blah.com',
     join_url: 'www.blah.com',
     recordings: conferenceOpts.recordings,
     user_settings: conferenceOpts.user_settings,
@@ -168,8 +167,8 @@ test('renders adobe connect link', function() {
       {
         recording_id: "954cc3",
         title: "Conference",
+        playback_url: 'www.blah.com',
         duration_minutes: 0,
-        playback_url: null,
         playback_formats: [
           {
             type: "statistics",