RFR: 8265309: com/sun/jndi/dns/ConfigTests/Timeout.java fails with "Address already in use" BindException

[Aleksei Efimov]

Hi,

`com/sun/jndi/dns/ConfigTests/Timeout.java ` was seen failing intermittently with "Address already in use" `BindException`. The reason of this failure is that `disconnect` call in JNDI `DnsClient` fails to rebind the datagram socket to the original port during `disconnect` call (the failure is in `DatagramChannel::repairSocket`).   
Since Datagram socket is not reused and closed after the failure `finally` block with the `disconnect` call can be removed.

The fix was tested with all available JNDI/DNS tests, and no failures related to the change were observed.

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Commit messages:
 - 8265309: com/sun/jndi/dns/ConfigTests/Timeout.java fails with "Address already in use" BindException

Changes: https://git.openjdk.java.net/jdk/pull/4227/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4227&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265309
  Stats: 30 lines in 1 file changed: 0 ins; 5 del; 25 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4227.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4227/head:pull/4227

PR: https://git.openjdk.java.net/jdk/pull/4227