Fix ignore host name

[Aleksandr-Melnikov]

1. "Security ignore" enum had values 0,1,2,3 but it was used with or operator. So, it was changed to hex values 0x01, 0x02, 0x04, 0x10.
2. If "Host" header is passed with the request, then it supposed to be used in ssl hostname validation instead of ip address that is used as hostname part of url. In such case we still can perform peer cert validation but omit host name validation.