[docker] Keep flower compatible with celery v4
@@ -56,7 +56,7 @@ RUN ./build/env/bin/pip install --no-cache-dir \
psycopg2-binary \
# Avoid Django 3 pulling
django_redis==4.11.0 \
- flower \
+ flower==0.9.7 \
# Contains fix for SparkSql show tables
git+https://github.com/gethue/PyHive \
# pyhive \
