Compiled translation when building the docker image (#2199)

Author: bmispelon

Dockerfile

@@ -45,5 +45,7 @@ RUN apt-get update \
 # copy project
 COPY . .
 
+RUN python -m django compilemessages
+
 # ENTRYPOINT is specified only in the local docker-compose.yml to avoid
 # accidentally running it in deployed environments.