Fix ansible update.sh.j2 template

deploy/ansible/roles/galaxy_media_site/templates/update.sh.j2

@@ -4,31 +4,31 @@
 
 set -e
 
-# Make sure this isn't being run as root
-if [[ $EUID = 0 ]]; then
-    echo "Don't run this as root - ubuntu is fine!"
+# Ensure run as root
+if [[ $EUID != 0 ]]; then
+    echo "Must be run as root - use sudo"
     exit 0
 fi
 
 # Source virtual environment and git pull
-cd galaxy-content-site
+cd {{ project_root }}
 source '{{ venv_root }}/bin/activate'
 git pull
 python -m pip install -r requirements.txt
-cd webapp
+cd {{ django_root }}
 
 # Collect any new static files for Nginx if neccessary
 python manage.py collectstatic --noinput
 
 # Migrate the database (if necessary)
-python manage.py migrate
+sudo -u www-data python manage.py migrate
 
 # Update file ownership to allow www-data to write logs/media
-sudo chown -R www-data:www-data webapp/logs
-sudo chown -R www-data:www-data webapp/media
+chown -R www-data:www-data webapp/logs
+chown -R www-data:www-data webapp/media
 
 # Restart the GMS web service
-sudo service gms restart
+service gms restart
 
 echo ""
 echo "~~~ Restarted Galaxy Media Site ~~~"