RFR 8166359/9, java/net/URLPermission/nstest/lookup.sh fails if proxy is set, since fix for JDK-8161016

[Felix Yang]

Hi all,
    please review the following test fix. It explicitly disables proxy to make 
sure the test not affected by different environment configuration.

Bug:
    https://bugs.openjdk.java.net/browse/JDK-8166359

Webrev: 
     http://cr.openjdk.java.net/~xiaofeya/8166359/webrev.00/ 
<http://cr.openjdk.java.net/~xiaofeya/8166359/webrev.00/>

Thanks,
Felix