biology/diamond: Update to version 0.8.30

Upstream changes:

• slightly improved sensitivity
• added option to report unaligned queries: --unal (0=no, 1=yes)
• pairwise, XML and SAM format will report unaligned queries by default
• added option to filter alignments by subject cover (--subject-cover)

Approved by: swills (mentor)
Differential Revision: https://reviews.freebsd.org/D9000