RFR: 8168468: [TEST_BUG] CheckNullEntity.java fails to compile

[Ivan Gerasimov]

Hello!

A compilation issue with the regression test was observed due to 
ambiguity between two X509ExtendedTrustManager classes.

The fix is to organize the imports.

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8168468
WEBREV: http://cr.openjdk.java.net/~igerasim/8168468/00/webrev/

Would you please help review this?

With kind regards,
Ivan