Log Message:
net/unison-snapshot: import unison-2.51.2.20200221

Unison is a file-synchronization tool for Unix and Windows. It
allows two replicas of a collection of files and directories to be
stored on different hosts (or different disks on the same host),
modified separately, and then brought up to date by propagating
the changes in each replica to the other.

This package contains a snapshot of the git repository to get
bugfixes not in the latest release.