ci: integration: Add an extra level of quoting for augeas set options

ci: integration: Add an extra level of quoting for augeas set options

Both log filters and log outputs expect string values, however, augeas
apparently requires an extra level of quotes apart from the ones we
pass via shell (see comment [1]) to work properly, otherwise augeas
ignores the value and returns 0.
Without this fix we don't set libvirt's log level to debug, we don't
set logging to a file and hence we don't include the logs in CI
artifacts in case the test suite fails.

[1] https://github.com/hercules-team/augeas/issues/301#issuecomment-143699880

Signed-off-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>