Add keepalive for redis client to make the connections reliable

[NomadXD]

In a case of a sudden connection loss Redis clients are not able detect network problems, and will be listening for Pub/Sub messages on a broken TCP connection for hours, making Pub/Sub unusable.

This is a common issue in redis clients and some redis clients like lettuce are already fixed . redis/lettuce#1428

Refer to this issue for more info: redis/redis#7855