Extra override for the 'Unrecognized username or password' error message

I think this is a valid request, because

Unrecognized username or password. Forgot your password?

should be something like

Unrecognized username / email or password. Forgot your password?

@adam_b could you prepare a MR to fix this?

@adam_b
As suggested, one more field in the config form is added and that holds the error message.

This won't have any effect yet?

@Anybody
It is updated.