devel/upnp: Update to 1.12.1

[salvadore]

Summary

• Fix bug about setsockopt(IP_MULTICAST_IF) on 64-bit CPUs.
• Stop using usleep when using newer POSIX C source as it is now deprecated.
• Add Os/UserAgent information to UpnpActionRequest and UpnpFileInfo.
• Add CtrlPtIPAddr to UpnpFileInfo class.
• List: Add extern C for C++ users.

Test Plan

I tested successfully with poudriere on {11.3,12.1}-RELEASE and 13.0-CURRENT(both amd64 and i386) the port itself and the ports that depend on it (with the needed option enabled, of course), which do not need PORTREVISION bump as compatibility is not broken (soname remains libupnp.so.16).

[tcberner]