hg: jdk-updates/jdk11u-dev: 8185898: setRequestProperty(key, null) results in HTTP header without colon in request

[christoph.langer at sap.com]

Changeset: 107122c0a412
Author:    michaelm
Date:      2019-08-12 11:24 +0100
URL:       https://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/107122c0a412

8185898: setRequestProperty(key, null) results in HTTP header without colon in request
Reviewed-by: chegar, dfuchs

! src/java.base/share/classes/sun/net/www/MessageHeader.java
+ test/jdk/sun/net/www/B8185898.java