Fix: inProgress was not cleared when property was not found

Change-Id: I7d87bb235a4458f3a25614ffade5b32ac9b95a7f
Reviewed-on: https://pirx.atteo.com/gerrit/558
Tested-by: Mr. Jenkins
Reviewed-by: Sławek Piotrowski <sentinel@atteo.com>
Update README

Change-Id: Ib4d0a570f23e0467fd7e0db9918288cdc1de5e3f