Attempt to fix pgadmin error in tests

Author: ericallam

docker/docker-compose.yml

@@ -31,7 +31,7 @@ services:
     environment:
       PGADMIN_DEFAULT_EMAIL: [email protected]
       PGADMIN_DEFAULT_PASSWORD: admin
-      PGADMIN_DISABLE_POSTFIX: true
+      PGADMIN_DISABLE_POSTFIX: "true"
     volumes:
       - pgadmin-data:/var/lib/pgadmin
       - ./pgadmin/servers.json:/pgadmin4/servers.json