The signal used to be emitted only on reset or when tests are actually removed during sweep phase:
thus the 'run tests' button in test panel stayed disabled if the panel was opened while tests were
scanned.

Change-Id: I274c9d03f1e1140c8aa375f92465c5a0c866cd62
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>