Restore ONLY_FOR_ARCHS
Fix a few rc script issues that mainly affected the plexpass slave port


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@373634 35697150-7ecd-e111-bb59-0022644237b5
Simplify ONLY_FOR_ARCHES wording

Full sententes look ugly when the message is produced

Submitted by:	danfe


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@373635 35697150-7ecd-e111-bb59-0022644237b5