entr: Update to 4.3

pkgsrc changes:
- Update HOMEPAGE and MASTER_SITES to current ones

Changes:
== 4.3: September 25, 2019
- Move hosting from bitbucket.org to github.com
- Rename tag names from entr-X.Y to X.Y
- Replace hg with git as a dependency for system-test.sh

== 4.2: March 28, 2019
- Use pledge(2) on OpenBSD
- New '-a' option enables response to events that occur while the utility is
  running
- Error messages direct users to http://eradman.com/entrproject/limits.html
- Correctly report error when a file cannot be reopened

(leot)