biology/clustalw: Fix license, take maintainership

[jwb]

Summary

biology/clustalw: Fix license, take maintainership
Approved by jrm (mentor) or wen (mentor)
Differential to be added to commit message

I'm stumped as to how this port got marked RESTRICTED. The license is LGPL:

http://www.clustal.org/clustal2/

Maybe the license was changed at some point?

Test Plan

portlint -AC: looks fine
Passed poudriere on {10.4,11.1}-{amd64,i386}
Tested in production