RFR 8214014 : Remove vestiges of gopher: protocol proxy support

[Roger Riggs]

Please review the removal of some left over references to the gopher 
protocol related to proxies.
Most are related to properties or setting up proxies (for gopher).
Please check in javax.print that the inclusion of the gopher protocol is 
no longer needed.

Webrev:
  http://cr.openjdk.java.net/~rriggs/webrev-gopher-remove-8214014/

CSR:
  https://bugs.openjdk.java.net/browse/JDK-8214301

Thanks, Roger

p.s. fyi, this patch assumes a previous patch cleaning up property 
initialization (4947890)