When copying templates or files with the
process-templates.py's shutil, ignore cases when
the source and the destination are same files.
This allows the following scenario:
- Symlink t-h-t from the installed package to a work dir
- Process j2 templates with overwrite in the work dir
Required-by: https://review.openstack.org/#/c/542875
Change-Id: I9a9c32f05fde325709998f4fe8bc7fef6c25b5c5
Signed-off-by: Bogdan Dobrelya <bdobreli@redhat.com>