Log Message:
net/unison: Update to 2.52.1

2.52.1 is a maintenance release in the 2.52 series. All users are
strongly encouraged to migrate all systems on which they use unison to
2.52.1. Fairly soon, only reports about 2.52.1 will be allowed in the
issue tracker.

2.52.1 is expected to be the last release in the 2.52 series, absent
prompt (7 days) discovery and reporting of a serious problem.

After a 7-day hold, work towards 2.53 may be merged. In particular
this will include changing the minimum ocaml version to 4.08. Once
this happens, there will not be any more 2.52.x releases, as no one
contributing to unison maintenance is interested in supporting old
versions. Of course, the license gives anyone the ability to create or
cherry-pick fixes and to use the fixed versions.

Changes in 2.52.1

Released 2022-05-08

- Deprecate ocaml < 4.08: 2.53.0 will require 4.08 or higher
- Add man page
- Remove rsh:// URI scheme (ssh:// of course remains).
- Significant bugfixes and minor improvements
- Deprecate "backups" preference (see manual for alternatives)
- Deprecate "stream" and "halfduplex" preferences