Since swiftclient 4.0.1, sha256 is used when generating tempurl
signature[1].
This change extends the regex pattern to assert signatues so that it
can accept both sha1(old) and sha256(current).
[1] https://review.opendev.org/c/openstack/python-swiftclient/+/845157
Change-Id: I1589adbe4501b1c678f197b9c0f67b716c341b2d