mail/rspamd: Update to 3.0

[yasu]

Summary

• Pet portclippy
• Reformat Makefile with portfmt

Changelog: https://rspamd.com/announce/2021/08/19/rspamd-3.0.html
PR: 257944
Approved by: maintainer timeout (> 1 month), meta (mentor),

		ygy (mentor)

Test Plan

Build succeeds with poudriere and 13.0-RELEASE amd64 jail

[yasu]

Add "Differential Revision:" to commit message.

[ygy]

Looks good to me!