Move FLASK_APP to our wrapper script

Dockerfile

 FROM registry.git.autistici.org/ai3/docker/s6-base:master AS base
-
 RUN apt-get -q update && \
     env DEBIAN_FRONTEND=noninteractive apt-get -qy install --no-install-recommends \
         python3-flask python3-sqlalchemy python3-flask-sqlalchemy python3-cheroot \
@@ -8,17 +7,12 @@ RUN apt-get -q update && \
     rm -fr /var/lib/apt/lists/*
 
 FROM base AS build
-
 ADD . /src
 WORKDIR /src
 RUN python3 setup.py bdist_wheel
 
 FROM base
-
 COPY --from=build /src/dist/*.whl /tmp/wheels/
 COPY conf/ /etc/
 COPY feedbackloop.sh /usr/local/bin/feedbackloop
-
 RUN cd /tmp/wheels && pip3 install *.whl && rm -fr /tmp/wheels
-
-ENV FLASK_APP=feedbackloop.main:create_app

feedbackloop.sh

 #!/bin/sh
 
+export FLASK_APP=feedbackloop.main:create_app
+
 exec flask "$@"