add redis hostname for immich

tasks/immich.yml

@@ -58,6 +58,7 @@
       - "/etc/localtime:/etc/localtime:ro"
     env:
       DB_HOSTNAME: "immich_postgres"
+      REDIS_HOSTNAME: "immich_redis"
       DB_PASSWORD: "{{ IMMICH_DB_PASSWORD }}"
       DB_USERNAME: "{{ IMMICH_DB_USERNAME }}"
-      DN_DATABASE_NAME: "{{ IMMICH_DB_DATABASE_NAME }}"
+      DB_DATABASE_NAME: "{{ IMMICH_DB_DATABASE_NAME }}"