This change fixes few linting errors which are discovered by newer
linters.
- bashate: consistent 4 chars identation
- python unamed Exceptions
- python space around operators
- python space after # comments
- python unused imports
- python unknown escapes (errors after py36)
- python double newline before methods
Change-Id: I5d2f37d1c820b1983355be60c09de581a72e08e0
Needed-By: https://review.opendev.org/#/c/665445/