Remove explicit dependency of libldap from LIB_DEPENDS.
This Makefile already defines USE_OPENLDAP=yes, which causes bsd.ldap.mk
to add libldap.so to LIB_DEPENDS.

If WANT_OPENLDAP_SASL is defined in make.conf,
then this port would have two dependencies,
  (1) dependency on sasl-enabled openldap package
  (2) dependency on non-sasl openldap package

This is wrong, so removing the duplicate dependency is the right fix.
This was discovered by poudriere.
During the build of x11-toolkits/pango, glib-mkenums from the devel/glib20 port
is executed.  However, glib-mkenums is a perl script, so we
need to specify "perl5" in USES.  This allows us to use perl to build this port,
without creating a runtime dependency on perl.

See:
http://lists.freebsd.org/pipermail/freebsd-ports/2006-December/037249.html

There might be a better fix upstream, but this quick fix allows us to build
all the FreeNAS ports with poudriere.