[8u-dev] RFR 8170278 : ticket renewal won't happen with debugging turned on

[Ivan Gerasimov]

Hello!

It was reported that there's broken behavior exposed when the debug mode 
is turned on, which is due to KerberosTicket.toString() throwing an 
exception, if the ticket was already destroyed.

The proposed fix is in fact the backport of a tiny portion of JDK-8043071.

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8170278
WEBREV: http://cr.openjdk.java.net/~igerasim/8170278/00/webrev/

Would you please help review?

With kind regards,
Ivan