Undefined error code "MP_CONNECTION_ERROR"

[Yanmei-Liu]

In section 3, we wrote

If endpoint receives an unexpected value for the transport parameter
   "enable_multipath", it MUST treat this as a connection error of type
   MP_CONNECTION_ERROR and close the connection.

But in section 13, we don't have this error code definition.

[qdeconinck]

Sounds like a duplicate of #136 ? :)

[Yanmei-Liu]

Yep, let's discuss in #136.