📌 Fix flower Docker image, pin version (#396)

Co-authored-by: Kyler <39353605+fisher60@users.noreply.github.com>
Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

src/docker-compose.yml

@@ -112,7 +112,7 @@ services:
     # You also have to change the flower command
   
   flower:
-    image: mher/flower
+    image: mher/flower:0.9.7
     networks:
       - ${TRAEFIK_PUBLIC_NETWORK?Variable not set}
       - default