RFR 8163149/9, Typo in java.net.http.AuthenticationFilter

[Felix Yang]

Hi there,

   please review a simple patch for java.net.http.AuthenticationFilter. 
There is a typo in the code. "Proxy-Authentication" should be replaced 
with "Proxy-Authenticate"

Bug: https://bugs.openjdk.java.net/browse/JDK-8163149

Webrev: http://cr.openjdk.java.net/~xiaofeya/8163149/webrev.00/

Thanks,

Felix