Do not use versioned v2.0 endpoint in Pike

This patch replaces v2.0 endpoint with versionless for keystone_authtoken
section.

The  keystone_ec2_uri in ec2authtoken is set to use v3 explicitly as
versionless endpoint doesn't exist for ec2

Change-Id: I8419ac294b544108b8588fb81c350bd5839c9e49
Related-Prod: PROD-18958
1 file changed