Fix docs example using generator config files
Fix docs example using generator config files

This commit fixes the namespace usage in the example config files for
the config generator docs. Previously the example used the
nova.compute namespace twice, however based on the other examples
above one is a typo and should be nova.common instead.

Change-Id: I426f4a3b97124b4a7eecda52ce52232cdcbc32ca

varunarya10/oslo.config,magic0704/oslo.config,tianshan/oslo.config,JioCloud/oslo.config,shad7/oslo.config