Remove #noqa from gettextutils imports

Removed #noqa from gettextutils and added them to import_exceptions.
I think it is better to specify option in one place (tox.ini) than
every time take care that you do not forget to specify this tag.

Also removed a few unused imports that were revealed in the process.

Change-Id: Ic4ca9cf374870075a36b88269ff8aea5a8e24a90
Merge "Remove #noqa from gettextutils imports"