Remove expired ports:
2017-04-30 devel/ccons: Unfetchable for more than six months (google code has gone away)
2017-04-30 chinese/fortune: Unfetchable for more than six months (google code has gone away)
2017-05-05 benchmarks/gobench: Builds each time it runs
2017-04-30 sysutils/grok: Unfetchable for more than six months (google code has gone away)