[11u] RFR: 8183369: RFC unconformity of HttpURLConnection with proxy

[Alex Kashchenko]

Hi,

Please review the backport of JDK-8183369 to 11u:

Bug: https://bugs.openjdk.java.net/browse/JDK-8183369

Original change: https://hg.openjdk.java.net/jdk/jdk/rev/0ba758a2b6f0

11u webrev: http://cr.openjdk.java.net/~akasko/jdk11u/8183369/webrev.00/

Patch to HttpURLConnection applies cleanly, patch to HttpURLConWithProxy 
test was adjusted because mainline changes depend on JDK-8227539 that 
was added in 14.

-- 
-Alex