Author: Mark Nelson
MDL-60969 auth_ldap: replace hardcoded strings in config settings
http://git.moodle.org/gw?p=moodle.git;a=commit;h=dbe18cd3564e58f947da32a1132ce4abb5af287e
http://github.com/moodle/moodle/commit/dbe18cd3564e58f947da32a1132ce4abb5af287e
+ 3.5 en [auth_ldap_expiration_desc,auth_ldap]