Add support of "/{udp,tcp,proto}" suffix into $firewall_myservices, which
interpreted the listed items as port numbers of TCP services.

A service with no suffix still works and recognized as a TCP service for
backward compatibility.  It should be updated with /tcp suffix.

PR:		194292
MFC after:	1 week


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273201 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f