Move login command inside try so we clear env correctly

repo2docker/docker.py

@@ -190,7 +190,8 @@ class DockerEngine(ContainerEngine):
                 shutil.copy2(dc_path, new_dc_path)
 
             os.environ["DOCKER_CONFIG"] = d
-            proc = subprocess.run(
+            try:
+                subprocess.run(
                     [
                         "docker",
                         "login",
@@ -202,7 +203,6 @@ class DockerEngine(ContainerEngine):
                     input=password.encode(),
                     check=True,
                 )
-            try:
                 yield
             finally:
                 if old_dc_path: