Hang with QT 5.11.2 QSslConfiguration::defaultConfiguration()

With QT 5.11.2 and OpenSSL 1.1.1, a deadlock occurs when calling QSslConfiguration::defaultConfiguration() resulting in the qt application not loading.

This code block was added in 2015 15e26a6 to add this setting This setting is the default in QT > 5.4 and this setting no longer needs to be done in the client code.

This was discovered upstream in bitcoin in bitcoin#14359
The fix was to remove the code
bitcoin@2468471

After applying this commit, the client started as expected