Unexport HTTP proxy variables in autopkgtest

This works around lack of support for no_proxy, which breaks the tests on
Ubuntu autopkgtest. We don't actually need Internet access, so this is OK.

debian/changelog

@@ -5,6 +5,9 @@ ostree (2017.12-1) UNRELEASED; urgency=medium
     - Update symbols file
   * Add some post-release bug fix patches
   * Simplify autopkgtest now that test-local-pull seems to be stable
+  * Unexport HTTP proxy variables in autopkgtest to work around lack of
+    support for no_proxy, which breaks the tests on Ubuntu autopkgtest.
+    We don't actually need Internet access, so this is OK.
 
  -- Simon McVittie <smcv@debian.org>  Tue, 03 Oct 2017 19:14:14 +0100
 

debian/tests/gnome-desktop-testing

@@ -3,4 +3,12 @@
 set -e
 exec 2>&1
 
+# Ubuntu provides internet access via a proxy, but libostree doesn't need
+# that. However, libostree also doesn't support no_proxy, so it will try
+# to use Ubuntu's proxy for localhost, and fail to reach itself.
+unset ftp_proxy
+unset http_proxy
+unset https_proxy
+unset no_proxy
+
 exec gnome-desktop-testing-runner libostree