Code review comment for lp://qastaging/~danilo/linaro-android-build-tools/use-http-proxy

FWIW, without the seed file we got down to 28 mins for "repo sync" (from 44 mins with seed and no proxy, and 41 for initial run with the proxy) on https://android-build.linaro.org/jenkins/job/danilo_galaxynexus-jb-gcc47-aosp-blob/