This commit, fix a core dump on ypldap(8) related with memory allocation.
Also an example of how to set the ypldap.conf(5) properly is added to
examples files.
A new user _ypldap is required to be able to run ypldap(8) as well as
in a chroot mode.
Reviewed by: rodrigc (mentor), bjk
Approved by: bapt (mentor)
Relnotes: Yes
Sponsored by: gandi.net
Differential Revision: https://reviews.freebsd.org/D4744
