Commit f2a6f0b8dba025102a90b9ae30b70096c2bd07da aimed to fix possible issue with connecting to the database during the connector start and retry the connector start if there are any such issues. As reported in this Zulip topic, it seems that this change actually cause a regression when before restart was retried, but with this change it stops the connector without retry. Logs from Debezium 2.1.2.Final when connector is restarted in a loop and from Debezium 2.2.0.Alpha3 when after the first restart connector is stopped are attached (both from the original Zulip thread).

There are more issue with this change, e.g. BaseSourceTask.start() method now doesn't start the connector (removed here) or the change assumes that the connector restart is done in a way that stop(restart=true); start() is called, but e.g. EmebeddedEngine still calls it as stop(restart=false); start(), which is wrong.