Merge pull request #15130 from edx/douglashall/ENT-388

ENT-388 Fix formatting issues with LMS account activation email.

lms/templates/emails/activation_email.txt

@@ -4,9 +4,9 @@ ${_("You're almost there!  Use the link to activate your account to access engag
 "you have activated it.").format(platform_name=platform_name)}
 
 % if is_secure:
-  https://${ site }/activate/${ key }
+https://${ site }/activate/${ key }
 % else:
-  http://${ site }/activate/${ key }
+http://${ site }/activate/${ key }
 % endif
 
 ${_("Enjoy learning with {platform_name}.").format(platform_name=platform_name)}