Do not log the full session ID

According to our logging guidelines we should not log sensitive data:
https://wiki.openstack.org/wiki/Security/Guidelines/logging_guidelines

This patch changes all log statements to log only the last 5 characters
of the session ID, so we can still have something for debugging
purposes.

Change-Id: I0e524eeca9ad3417a71039681ca1d64d589346fe
Imported Translations from Transifex

Change-Id: I592248213a48bfac737ea81d25c620d2a85355c1
The 'result' variable in RetryDecorator may be undefined

Define and initialize the 'result' variable before the try block.

Change-Id: Ic2d77e7138146b249f4ba8895019e2a9773f1651
Merge "The 'result' variable in RetryDecorator may be undefined"
Merge "Do not log the full session ID"