fixed cross icon issue on set date dialog inside schedule tab

AUTHORS

@@ -207,3 +207,4 @@ Phil McGachey <phil_mcgachey@harvard.edu>
 Sri Harsha Pamu <kmitharsha@gmail.com>
 Cris Ewing <cris@crisewing.com>
 Carlos de La Guardia <carlos@jazkarta.com>
+Amir Qayyum Khan <amir.qayyum@arbisoft.com>

lms/templates/ccx/schedule.html

@@ -32,7 +32,7 @@
 <section id="enter-date-modal" class="modal" aria-hidden="true">
   <div class="inner-wrapper" role="dialog">
     <button class="close-modal">
-      <i class="fa-remove"></i>
+      <i class="icon fa fa-remove"></i>
       <span class="sr">
         ${_("Close")}
       </span>