--preferred-chain not taking effect

[FelixSchwarz]

@mle-ii

For sure, thank you. Definitely something we'll need to consider doing. I didn't realize our version was that far behind what's current

Short version: Try certbot 1.11.0-2 from epel testing.

For more details please read:

Certbot update for CentOS 7: use --prefered-chain to select a shorter chain

J…