Update to upstream release 1.9.2

Detailed maintainer log:

• Update to mutt 1.9.2
• Bring ats date-conditional back as a local patch file
  • Due to the patch not having versioning an update can break the port if the hash of the file changes
• Update greeting patch to 1.9.1

PR: 224374
Submitted by: dereks@lifeofadishwasher.com (maintainer)
Differential Revision: https://reviews.freebsd.org/D13509