Remove expired ports:

2020-03-29 security/w3af: Uses deprecated version of Python
2020-03-30 sysutils/duplicity-devel: Obsolete now, use sysutils/duplicity instead
2020-03-31 net-mgmt/tornova: Use EOL'd Python 2.7
2020-03-31 audio/py-ogg: Unmaintained, uses EOLed python27
2020-03-31 net-mgmt/onionlauncher: Use EOL'd Python 2.7
2020-03-31 databases/mongodb34: EOL January 2020; See https://www.mongodb.com/support-policy
2020-03-31 graphics/sane-frontends: Unmaintained upstream, no consumers left
2020-03-31 lang/ruby24: Move to a new version (lang/ruby26 or above). Ruby 2.4 is in security maintenance phase and planned for EOL on March 31, 2020
2020-03-31 databases/pgpool: Reached EOL at 2019-10-31, please use pgpool-II-35 or higher
2020-03-31 net/pygopherd: Unmaintained, uses EOLed python27
databases/mongodb34-tools: Part of expired MongoDB 3.4