[7u6] request for approval, 7147407: remove never used debug code in DnsClient.java

[Xuelei Fan]

Hi,

This is a request to backport a JDK 8 fix into JDK 7u6:
     7147407: remove never used debug code in DnsClient.java

The fix has already been pushed to JDK 8:
     http://hg.openjdk.java.net/jdk8/tl/jdk/rev/a4e3dde9a8a7

The code changes for jdk7u6 are identical to the ones in jdk8.

I intend to push it to
     ssh://hg.openjdk.java.net/jdk7u/jdk7u-dev-gate/jdk

Regards,
Xuelei