proper test log configuration

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
workaround okhttp bug 662

as suggested in [1], return null credentials when the same host:port
provides the same challenge multiple times.

[1] https://github.com/square/okhttp/issues/662

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
Merge branch '430772_proxy-auth-endless-407-loop'
Updating to account for OkHttp looping indefinitely on unsupported authentication schemes