fix: show system timezone in certificate request

lms/templates/emails/certificate_request_notification.html

@@ -1,6 +1,6 @@
 <p> {{ _("Hey {0}").format(member_name) }} </p>
 <br>
-<p> {{ _('Your evaluation for the course {0} has been scheduled on {1} at {2} {3}.').format(course, date, start_time, timezone) }}</p>
+<p> {{ _('Your evaluation for the course {0} has been scheduled on {1} at {2} ({3} time).').format(course, date, start_time, timezone) }}</p>
 <br>
 <p> {{ _("Your evaluator is {0}").format(evaluator) }} </p>
 <br>