escape string literal also

lms/templates/certificates/_accomplishment-banner.html

@@ -51,7 +51,7 @@ from django.template.defaultfilters import escapejs
                           share_text: '${facebook_share_text | escapejs}',
                           share_link: '${share_url}',
                           picture_link: '${full_course_image_url}',
-                          description: '${_('Click the link to see my certificate.')}'
+                          description: '${_('Click the link to see my certificate.') | escapejs}'
                           });">
                           <i class="icon fa fa-facebook-official" aria-hidden="true"></i>
                           <span class="action-label">${_("Post on Facebook")}</span>