Correção no docker-file conforme instrução da COTIN

docker/Dockerfile

@@ -81,9 +81,6 @@ RUN echo $'\n\n'SECRET_KEY=`python manage.py generate_secret_key` >> ${HOME}/sig
 # Prepare run script to start application server
 RUN chmod +x ${HOME}/bin/run_sigi
 
-# Data migration
-RUN python manage.py migrate
-
 # Static files
 RUN python manage.py collectstatic --noinput --clear
 
@@ -97,4 +94,9 @@ EXPOSE 80/tcp 443/tcp
 ENV DEBIAN_FRONTEND=teletype
 
 VOLUME ["/srv/interlegis/sigi/media"]
+
+# Data migration
+RUN python manage.py migrate
+
+# Start web server
 CMD service nginx start && /srv/interlegis/sigi/bin/run_sigi