Flag to disable username as password

[harrisonSoS]

In 2017 there was a patch that...

uses username as password during brute force (once all possible username/password combinations have been tried. Does not apply to --userpass)

I rarely use this function and it uses up a valid attempt for each user, bringing lockouts all the more closer.
A flag that counters this behaviour would be a great quality of life feature.
Thank you for the tool! :)