Use a fixed Debian mirror rather than relying on httpredir
This is another attempt at a stable nightly package build. The currently most common error is:
```
E: Failed to fetch http://httpredir.debian.org/debian/pool/main/p/patch/patch_2.7.5-1_amd64.deb Error reading from server. Remote end closed connection [IP: 5.153.231.35 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
The command '/bin/sh -c apt-get update && apt-get -y install bison debhelper devscripts dpkg-dev curl git libapr1-dev libcurl4-openssl-dev libkrb5-dev libsvn-dev python-all-dev software-properties-common thrift-compiler' returned a non-zero code: 100
```
Reviewed at https://reviews.apache.org/r/51301/
diff --git a/builder/deb/debian-jessie/Dockerfile b/builder/deb/debian-jessie/Dockerfile
index 2279332..4a70359 100644
--- a/builder/deb/debian-jessie/Dockerfile
+++ b/builder/deb/debian-jessie/Dockerfile
@@ -10,12 +10,21 @@
# See the License for the specific language governing permissions and
# limitations under the License.
#
-FROM debian:jessie-backports
+FROM debian:jessie
WORKDIR /aurora
ENV HOME /aurora
ENV DEBIAN_FRONTEND noninteractive
+# The default httpredir mirror is a common source for flaky docker builds.
+# Use an explicit mirror instead (https://github.com/docker-library/buildpack-deps/issues/40)
+RUN echo \
+ 'deb http://mirrors.kernel.org/debian/ jessie main\n \
+ deb http://mirrors.kernel.org/debian/ jessie-updates main\n \
+ deb http://mirrors.kernel.org/debian/ jessie-backports main\n \
+ deb http://security.debian.org jessie/updates main\n' \
+ > /etc/apt/sources.list
+
RUN apt-get update && apt-get -y install \
bison \
debhelper \
