Make test numbers unique

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t1506-rev-parse-upstream.sh b/t/t1507-rev-parse-upstream.sh
similarity index 100%
rename from t/t1506-rev-parse-upstream.sh
rename to t/t1507-rev-parse-upstream.sh