Remove Swift s3api fix now that it is patched upstream

We patched swift-proxy-server/proxy-server.conf to fix the S3 API, which was missing the /v3 path for Keystone:

[filters:s3token]
auth_uri = http://{{ ansible_default_ipv4.address }}:5000/v3

This patch can now be removed, as the kolla-ansible project has now fixed this bug upstream.