This change allows connecting to a NVT with an empty username and empty password.
Was testing with an ONVIF NVT which was set to no authentication. However this NVT complained when WS-Security (with empty username/password) was sent.
The empty username and password check is removed and WS-Security is only used when there is a username and password
Coverage increased (+0.2%) to 94.106% when pulling 40913e3825b741e381f57651e5c56d8be7ca5258 on RogerHardiman:master into d731908cb6f45b859beb36dfa64e9447df39d062 on agsh:master.
This change allows connecting to a NVT with an empty username and empty password. Was testing with an ONVIF NVT which was set to no authentication. However this NVT complained when WS-Security (with empty username/password) was sent. The empty username and password check is removed and WS-Security is only used when there is a username and password