Log Message:
security/clamav: update to 0.103.10

pkgsrc change:

* Do not always include mail/libmilter/buildlink3.mk in Makefile.
* Use clamav-unit-test PKG_OPTIONS instead of deprecated unit-test.
* pkglint clenn up.

0.103.10

ClamAV 0.103.10 is a critical patch release with the following fixes:

- Upgrade the bundled UnRAR library (libclamunrar) to version 6.2.10.
  - GitHub pull request: https://github.com/Cisco-Talos/clamav/pull/1009