fix: update to artic 1.2.2

[thomasbtf]

The version muscle used in artic was set to >=3.8. As muscle published version 5.1, the newer version is now used.
However, the 5.1 version has a different clit which breaks artic and thus ncov2019-artic-nf:

Running: muscle -in some.muscle.in.fasta -out some.muscle.out.fasta

Invalid command line
Unknown option in

This PR updates the artic version, which includes a bug fix for the problem described above.

See artic-network/fieldbioinformatics#105 for more information.