lang/go security problem on one but not the other

[Rob Belics]

I have a server and my workstation. Both run FreeBSD 10.2-RELEASE. Both had
lang/go version 1.4 on them. lang/go version 1.5 was released in ports and
it builds on my local workstation, including reinstalling version 1.4.2
but, on the server, it complains about the previous security
vulnerabilities and won't build.

I tried uninstalling both and deleted the distifles but that didn't change
anything. Why and what should I do?