RestClientMultipleHostsIntegTests testNodeSelector fails on windows

[albertzaharovits]

There's a few of LL client failures, all of them on 6.x and windows:

java.lang.AssertionError: expected:<Connection refused> but was:<null>
	at __randomizedtesting.SeedInfo.seed([429EEC8C470749C5:26A699538C5AFAE7]:0)
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at org.elasticsearch.client.RestClientMultipleHostsIntegTests.testNodeSelector(RestClientMultipleHostsIntegTests.java:217)
	....

that @nik9000 's commit 045f76d should have fixed this, but does it really? The message is null and not different. But the fix does appear to have worked on master yet not 6.x .

6.x failures:
https://groups.google.com/a/elastic.co/forum/#!searchin/build-elasticsearch/testNodeSelector|sort:date/build-elasticsearch/pIw1GjQIYAo/yf1OwCTgBAAJ
https://groups.google.com/a/elastic.co/forum/#!searchin/build-elasticsearch/testNodeSelector|sort:date/build-elasticsearch/BplpN0Ln0O4/jRVETj-TBQAJ
https://groups.google.com/a/elastic.co/forum/#!searchin/build-elasticsearch/testNodeSelector|sort:date/build-elasticsearch/45F3X_52Hd8/IPUoGGsdBQAJ

All of them tripping the same assertion about the connection error message.

[elasticmachine]

Pinging @elastic/es-core-infra

[nik9000]

Oh man! I thought I had fixed it..... Grumble Windows, grumble.