Shared object "libsodium.so.13" not found, required by, "dnscrypt-proxy"

[Piotr Kubaj]

Although I'm not on CURRENT, I can reproduce this problem on my PC's
running 10.1-RELEASE. It started on 31st January on only 1 PC and then
appeared on others after a few days. I update ports on a daily basis, so
that may be a hint. Strangely, only 3 of 5 of my computers are affected.
Once it appears during a reboot, it never goes away during other
reboots, so manual start of dnscrypt-proxy is required.

The same also happens with fuse on another computer, but that is a
separate issue.