Fix rest tests to use ip and port again instead of localhost and port.

buildSrc/src/main/groovy/org/elasticsearch/gradle/test/RestIntegTestTask.groovy

@@ -61,7 +61,7 @@ public class RestIntegTestTask extends RandomizedTestingTask {
         // references can be accessed as a fully configured
         project.gradle.projectsEvaluated {
             NodeInfo node = ClusterFormationTasks.setup(project, this, clusterConfig)
-            systemProperty('tests.rest.cluster', "localhost:${-> new URL('http://' + node.httpUri()).getPort()}")
+            systemProperty('tests.rest.cluster', "${-> node.httpUri()}")
             // TODO: our "client" qa tests currently use the rest-test plugin. instead they should have their own plugin
             // that sets up the test cluster and passes this transport uri instead of http uri. Until then, we pass
             // both as separate sysprops