ecf: workaround virtualprinter state on disk

If we ran the test yesterday and the printer ended up
being closed we will not be able to run the tests today.
Override the loaded till state to always have the till opened.

Change-Id: Ia5859c57cd12f0b840fe493a555f2d4592fcbf91
Rename db_person to default_person

Change-Id: I6b03bbf383a37f4c852e493649dd250a9e2bd88c