ci: Use host network driver

This helps those of us with specific proxy and DNS requirements.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
diff --git a/ci/build.sh b/ci/build.sh
index 0fa6238..c8046d4 100755
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -87,7 +87,7 @@
 ${HTTPS_PROXY_ENV}
 EOF
 )
-	$DOCKER_PREFIX docker build -t openpower/op-build-$distro - <<< "${Dockerfile}"
+	$DOCKER_PREFIX docker build --network=host -t openpower/op-build-$distro - <<< "${Dockerfile}"
 	mkdir -p output-images/$distro
 	run_docker openpower/op-build-$distro "./ci/build-all-defconfigs.sh output-images/$distro $PLATFORMS"
 	if [ $? = 0 ]; then