Redis commad -> command

https://github.com/antirez/redis/blob/673c9d702962a5618650108eaf4c5f38bcafe164/src/expire.c#L400

Comment From: trevor211

There is a PR fixing a bunch of typos, see #7414 . Safe to close @soloestoy .

Comment From: guoruibiao

Sorry, i didn't notice that.