Update appendixA-openssl-ca.txt

[cutrightjm]

CA bundle has to be in order intermediate > root; see this pastebin for example: https://pastebin.com/raw/dWe8KkJE .. If this isn't the case, you will recent an error "error 7 at 0 depth lookup: certificate signature failure" when manually verifying, or this in mongod.log: "SSL peer certificate validation failed: certificate signature failure"