Downloading docker images does not work on Windows

Changing build/download/docker_downloader.py to connect
docker engine in more default way i.e. taking engine
parameters from environment fixes this script.

Issue-ID: OOM-2223

Signed-off-by: Samuli Silvius <s.silvius@partner.samsung.com>
Change-Id: Iddf69593bb4cf4596e713c8d537a90424c5925ef
diff --git a/build/download/docker_downloader.py b/build/download/docker_downloader.py
index d83f682..27dde12 100755
--- a/build/download/docker_downloader.py
+++ b/build/download/docker_downloader.py
@@ -40,7 +40,7 @@
         self._save = save
         try:
             # big timeout in case of massive images like pnda-mirror-container:5.0.0 (11.4GB)
-            self._docker_client = docker.client.DockerClient(version='auto', timeout=300)
+            self._docker_client = docker.from_env(timeout=300)
         except docker.errors.DockerException as err:
             log.exception(
                 'Error creating docker client. Check if is docker installed and running'