After updating your site to use REDIS cache edit your
Take a look at the end of the file. There will be a
DEFINE there with the cache salt. Probably it will be at the last line of the script.
DEFINE line a dozen lines above (in order to have it above "stop editing" remark), save the file and clear all caches with
ee clean --all.
If I'm not missing anything will be good to go, then.