Called when ODPHTTPAuthChallengeListenerDelegate protocol is implemented by the class.
User Name contains the previous value on input.
Usage
-(void) onHTTPAuthChallenge:(NSString*)host forUser:(NSString*)userName withRealm:(NSString*)realm
{
NSLog("%@--%@--%", host, userName, realm);
[ODPClientListeners httpAuthChallengeResult:YES forUser:"mobile" withPassword:@"Ntwatch"];
}