Update Dockerfile

Dockerfile

@@ -23,11 +23,13 @@ COPY --chown=user . $HOME/app
 # Install any needed packages specified in requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt
 
+RUN export FLASK_APP=superset
+
 # Initialize the database
 RUN superset db upgrade
 
 # Create an admin user
-RUN export FLASK_APP=superset && superset fab create-admin \
+RUN superset fab create-admin \
     --username admin \
     --firstname Admin \
     --lastname User \