Group redis specific chan options

[icebob]

Before:

channels: {
    "test.failed_messages.topic": {
        group: "mygroup",
        maxRetries: 2,
        minIdleTime: 50,
        claimInterval: 50,
        processingAttemptsInterval: 10,
    }
}

After:

channels: {
    "test.failed_messages.topic": {
        group: "mygroup",
        maxRetries: 2,
        redis: {
            minIdleTime: 50,
            claimInterval: 50,
            processingAttemptsInterval: 10,
        }
    }
}