add %o: obfuscated remote IP address, removing the
last IPv4 byte or anything after the second colon (IPv6),
ie. "1.2.3." or "fe08:2:"
Also added the log patterns commonobf and combinedobf where instead of the remote host the obfuscated remote IP gets logged.
Purpose: better support for data privacy laws in the EU.
Tested against WildFly 15.0.1/linux.
Original pull request: https://github.com/undertow-io/undertow/pull/720