Use binary encoding setting for HSM

[jnweiger]

WHAT Needs to be Documented?

WHERE Does This Need To Be Documented (Link)?

WHY Should This Change Be Made?

owncloud/encryption#261 is merged, and has a comment
"When merged, docs relevant. Pls file a docs issue."

[jnweiger]

Confirmed in encryption 1.5.1-rc1: HSM works fine with both legacy base64 encoding and new binary encoding.

[mmattel]

To make it clear, with the upcoming release 1.5.1 of the encryption app, the HSM module correctly works and uses base64 and the new binary encoding (chosen based on the config setting).

This should be noted in https://doc.owncloud.com/server/admin_manual/configuration/server/security/hsmdaemon/

and added via #3710 (hsmdaemon install consistency and accuracy)

[mmattel]

Closed via #3710