Increase resolve timeout in unknown hosts test

The unknown hosts test is a simple test that fakes that resolving an
address results in an unknown host exception. The main purpose of this
test is to ensure that we log (and do not silently drop) when a host
fails to resolve. This test is subject to a race condition where the
timeout on the resolve request can fire before the resolve code finishes
executing (this race is exceptionally rare, because there are not
actually any DNS lookups being done here, just a mock resolve
implementation that throws an exception and that's where losing the race
can arise). This commit increases the timeout here to significantly
reduce the chance of a losing race causing a spurious test failure. This
increased timeout should not increase the runtime of the test, just make
failures less likely.

core/src/test/java/org/elasticsearch/discovery/zen/UnicastZenPingTests.java

@@ -441,7 +441,7 @@ public class UnicastZenPingTests extends ESTestCase {
             1,
             transportService,
             () -> Integer.toString(idGenerator.incrementAndGet()),
-            TimeValue.timeValueMillis(100)
+            TimeValue.timeValueSeconds(1)
         );
 
         assertThat(discoveryNodes, empty());