comms/owfs: backported minor changes

https://svnweb.freebsd.org/ports/head/comms/owfs/pkg-plist?r1=371247&r2=371246&pathrev=371247
Upgrade owfs to 2.9p7

Submitted upstream: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194261
owfs 2.9p8