Resolving dynamic ivy versions from different remote repositories causes NullpointerException

Trying to resolve a dynamic ivy version from different remote repositories can cause a NullpointerException which is caused by a ConcurrentModificationException which is originally caused by an unclosed HttpResponse. I've added a test that exposes that issue to the gradle integrationtests already: https://github.com/gradle/gradle/commit/a186c9b11a9bb91ded2ee8ad21764299bf4a4ce1