Previous execution of pipeline did not finish yet issue

[tomas-knap]

Happens for 2.3.2

1. debug a pipeline from pipeline canvas
2. when the pipeline is done (based on the events in the dialog), close that dialog
3. try to debug once again (quickly after the first finishes)

In that case, warning is often displayed that the previous execution of pipeline did not finish yet (but in the events table there is already info that pipeline finished!)

Problem: Although the debug dialog says pipeline is executed and finished, you cannot run pipeline (you have to wait for some more seconds)