Adjust t4201 to pass on Windows; a couple of test cases need to be
skipped on Windows which leads to a different shortlog than on Linux.
Let's just fix that by limiting the shortlog's commit range to traverse
only one commit: that guarantees that it does not matter how many test
cases were skipped.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>