František Kučera <franta-hg@frantovo.cz> [Tue, 26 Feb 2019 17:31:41 +0100] rev 235
JDBC drivers: fix 'Unsupported URL' – drivers might be called witrh wrong URLs and then they should (according to the JavaDoc) return null instead of throwing an exception.
This problem occurred when --test-connection was testing multiple connections in parallel.