Fix docker upload job to push -py2 images (#4576)

.circleci/config.yml

@@ -8,6 +8,7 @@ jobs:
       - run: docker build -f docker/Dockerfile --label gitsha1=${CIRCLE_SHA1} -t matrixdotorg/synapse:${CIRCLE_TAG} -t matrixdotorg/synapse:${CIRCLE_TAG}-py3 --build-arg PYTHON_VERSION=3.6 .
       - run: docker login --username $DOCKER_HUB_USERNAME --password $DOCKER_HUB_PASSWORD
       - run: docker push matrixdotorg/synapse:${CIRCLE_TAG}
+      - run: docker push matrixdotorg/synapse:${CIRCLE_TAG}-py2
       - run: docker push matrixdotorg/synapse:${CIRCLE_TAG}-py3
   dockerhubuploadlatest:
     machine: true
@@ -17,6 +18,7 @@ jobs:
       - run: docker build -f docker/Dockerfile --label gitsha1=${CIRCLE_SHA1} -t matrixdotorg/synapse:latest -t matrixdotorg/synapse:latest-py3 --build-arg PYTHON_VERSION=3.6 .
       - run: docker login --username $DOCKER_HUB_USERNAME --password $DOCKER_HUB_PASSWORD
       - run: docker push matrixdotorg/synapse:latest
+      - run: docker push matrixdotorg/synapse:latest-py2
       - run: docker push matrixdotorg/synapse:latest-py3
   sytestpy2:
     docker:

changelog.d/4576.misc

@@ -0,0 +1 @@
+Fix docker upload job to push -py2 images.