OmeroPy: src flake8 (III)

See https://trello.com/c/vnojR45Q/43-flake8-omeropy. This PR modifies the files under `components/tools/OmeroPy/src/omero/install` to let it comply with the PEP-8 style.

To review this PR:

- run flake8 on the files and check it is clean
- check the integration tests are still passing
- check the auto-generated configuration page is still working

/cc @ximenesuk 

--no-rebase

Note there is an extra space here that may be causing http://ci.openmicroscopy.org/view/Failing/job/OMERO-5.1-merge-docs/265/console to fail. I will investigate and push an extra commit if needed.