fix: remove accidently left-in debug output (in previous commit)
testbench: add -m option to chkseq

This permits to check files with a limited number of missing messages
testbench: adjust test to new config param defaults

The test didn't make sense with the new defaults, as the disk queue
was never activated. While at it, also improved test output a bit.
Merge branch 'v8-stable' of git+ssh://git.adiscon.com/git/rsyslog into v8-stable