keepalive: add ** overlooked in
83250442dc81
Caught by Yuya in D3326.
Differential Revision: https://phab.mercurial-scm.org/D3372
test-check-commit: don't run hg per commit
We aren't stress testing CPU.
$ time ./run-tests.py -l test-check-commit.t --timeout 600
(orig) 162.59s user 17.98s system 101% cpu 2:58.55 total
(new) 5.85s user 0.99s system 98% cpu 6.939 total