[9]RFR JDK-8160029: Security-libs tests need to avoid using jdk.testlibrary.Utils.getFreePort()

[John Jiang]

Hi,
Would you like to review this patch for removing unnecessary usages on 
jdk.testlibrary.Utils.getFreePort() from security-libs tests?
In OpenJDK, I find only sun/security/krb5/auto/KDC.java should be 
modified for this issue.
If I miss something, please let me know.

Issue: https://bugs.openjdk.java.net/browse/JDK-8160029
Webrev: http://cr.openjdk.java.net/~jjiang/8160029/webrev.00

Thanks!

John Jiang