remove duplicate call

docker_build.py

@@ -128,8 +128,6 @@
         c.get('odoo_scripts', 'odoo_type')) or 'odoo7'
     image = "%s/%s:latest" % (registry, project)
     logging.debug("Docker image: %s", image)
-    # detect if docker image already exists
-    docker_client = docker_api(base_url='unix://var/run/docker.sock')
     # TODO ensureconf
     if ensureconf:
         raise NotImplementedError