config_defaults.subtests: Fix all INI docstrings

Modify all docstrings in test INI files to support INI grabber.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
dockertest.envirotnment: Tweek ConfigINIParser

* enable NoOverwriteDict as all INI files are fixed
* skip simple comments (the one starting # not followed by :)

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>