Code Review Request 8144566, Custom HostnameVerifier disables SNI extension

[Xuelei Fan]

Hi,

Please review the update for JDK-8144566:

   http://cr.openjdk.java.net/~xuelei/8144566/webrev.00/

For HttpsURLConnection, the server name may be set after the TLS
connection and handshake has been initialized.  As may result in that
the server name does not present at TLS ClientHello messages.

This fix resets the server name for the initialized handshake for above
cases.

Thanks,
Xuelei