fixed startup entry point

Former-commit-id: c7553218

scripts/docker-entrypoint.sh

@@ -4,9 +4,9 @@ python3 manage.py makemigrations drugstone
 python3 manage.py migrate
 python3 manage.py createfixtures
 python3 manage.py cleanuptasks
-if [[ -z "$DB_UPDATE_ON_START" ]] || [[ "$DB_UPDATE_ON_START" = "0" ]]
+if [ -z "$DB_UPDATE_ON_START" ] || [ "$DB_UPDATE_ON_START" = "0" ]
 then
-echo "Update on startup disabled!"
+ echo "Update on startup disabled!"
 else
  python3 manage.py populate_db --update -a
  python3 manage.py make_graphs