Fix for Redis log spam

[panbed]

Redis should only be defined when it's set in the environment, otherwise it clogs up the logs if 127.0.0.1:6379 isn't available:

> server@1.0.0 start
> node dist/server.js

[dotenv@17.2.3] injecting env (1) from .env 
[ioredis] Unhandled error event: AggregateError [ECONNREFUSED]: 
    at internalConnectMultiple (node:net:1139:18)
    at afterConnectMultiple (node:net:1712:7)
[ioredis] Unhandled error event: AggregateError [ECONNREFUSED]: 
    at internalConnectMultiple (node:net:1139:18)
    at afterConnectMultiple (node:net:1712:7)
[ioredis] Unhandled error event: AggregateError [ECONNREFUSED]: 
    at internalConnectMultiple (node:net:1139:18)
    at afterConnectMultiple (node:net:1712:7)
[ioredis] Unhandled error event: AggregateError [ECONNREFUSED]: