mod_authnz_ldap: Fix language long names detection as short name.

trunk patch: http://svn.apache.org/r1824336
+1: ylavic, elukey, rpluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1824456 13f79535-47bb-0310-9956-ffa450edef68