Revert "Add parameter 'v8plus' for rsyslog version 8+"

This reverts commit 18a16ca041469d99bc0c5d27c46db62a06903ed8.
Update spec tests to support rsyslog_version fact

With commit 9fcacf58, the module uses the rsyslog_version fact in
templates. This commit updates the spec files to run cleanly with this
fact.