Fixes the failure of updating or deleting image empty property

When property protection feature enabled, end user couldn't uses
Glance v2 API to update or delete a property of an image successfully
which value is empty, client will receive a http 500 error and a
relevant error log could be found in glance-api service log.

Closes-bug: #1332103

Change-Id: I1f9f181cea714e6ba26388d125bb7023e7a14305
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Enable F821 check: undefined name 'name'

Enable F821 and fix usage of undefined variables.

In glance/common/client.py in BaseClient class image_iterator()
function returns instances of unexisting classes:
- SendFileIterator
- ImageBodyIterator
Since we have not these classes functionality now, we will use
utils.chunkreadable() function instead.

Delete image_iterator() function.

Change-Id: Ie1a8c66e5df2836e6e9aadfb1013d69fc6f710e6
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

Change-Id: I3c5b29616c8d76bed17dbd31a8f4fc7ccd2dd945
Trivial fix typo: Unavilable to Unavailable

This patch fixes a typo in an exception message.

Change-Id: I204b0bff94970d8743872cd184b8431d30dd1341
Merge "Fixes the failure of updating or deleting image empty property"
Merge "Do not log password in swift URLs in g-registry"
Merge "Trivial fix typo: Unavilable to Unavailable"
Merge "Enable F821 check: undefined name 'name'"