Omit ending dot from git commit summary line in obsolete deps scrubber

The git commit summary line is like a subject line in email. It should not end with a dot.

See e.g.

• https://git-scm.com/book/en/v2/Distributed-Git-Contributing-to-a-Project#_commit_guidelines
• source of any major open source project, e.g. Linux kernel commits
• more at https://github.com/Seravo/gnitpick#recommended-reads