Do not log password in swift URLs in g-registry

There was a debug level log with the locations added to it.
This change fixes the log to not contain that sensitive info.

Fixes bug 1348838

Conflicts:
	glance/registry/api/v1/images.py

Needed changes for Icehouse:
- use fixture.iteritems() instead of six.iteritems(fixture) in unit
  tests.

Change-Id: I3c5b29616c8d76bed17dbd31a8f4fc7ccd2dd945
(cherry picked from commit 28fdfdbaca81adcc94d5e6d57c55f7c985d6c512)
Merge "Do not log password in swift URLs in g-registry" into stable/icehouse