Database transactions are blocking on sqlite on the jenkins redhat and centos slaves

After adding a missing key generation task to 'zonelist import', repeated zonelist imports are now failing in the regression test test-cases.d/enforcer.ods-enforcer.zones_and_zonelist

The error seen is that the database transaction cannot start.

A short term workaround is in place on this test until time can be found to fix this properly.
Might help to check all the sqlite instances are compiled with HAVE_USLEEP as apparently this can be a culprit.

Proper fix is to implement consistent busy handling in the code.