Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary
failure in name resolution.

Should fix a buildbot failure.
diff --git a/Misc/NEWS b/Misc/NEWS
index 414db05..c4c8430 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -1008,6 +1008,9 @@
 Tests
 -----
 
+- Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary
+  failure in name resolution.
+
 - Avoid failing in test_robotparser when mueblesmoraleda.com is flaky and
   an overzealous DNS service (e.g. OpenDNS) redirects to a placeholder
   Web site.