Remove Parameter Update Response message

[Mališa Vučinić]

Mirja Kühlewind wrote (https://mailarchive.ietf.org/arch/msg/6tisch/tIJGaSM1AvaVjZN7BKHIfjgabJQ):

I'm putting this one question in the comments section because there is
no concern that it does not work as specified but I wonder about the
design of the Parameter Update Response Message. Given the Parameter
Update Message is a confirmable CoAP message that is transmitted
reliable and the content of the Parameter Update Response Message is
empty, why do you need to send the Parameter Update Response Message at
all?

[Mališa Vučinić]

Fix Issue #72: Remove Parameter Update Response message from the protocol.

→ <<cset 6da1cdc4fc03>>