fix rdr rules for expose when ip4_addr in NIC#<addr> form
fix rdr rules for expose when ip4_addr in NIC#<addr> form

we allow you to use the familiar for jail.conf users NIC#<addr> form for jail IP.
if this form is encountered, the "cbsd expose" must get rid of the interface part. Issue #623

cbsd/cbsd,cbsd/cbsd,cbsd/cbsd,cbsd/cbsd