Making "Namespaces" section truly optional

 * Added test on this case

Closes-Bug:  #1322737
Co-Authored-By: Nikolay Mahotkin <nmakhotkin@mirantis.com>

Change-Id: I35398da5963db8b5d085baa82dc21a5df64ec153
Merge "Making "Namespaces" section truly optional"