draft-ietf-jsonbis-rfc7159bis-03: recommendation to use UTF-8

Hi,

The JSONBIS WG decided to update recommendation on Unicode encoding to
be UTF-8. (For details see the RFC Editor's notes in the approval
message that will be sent out shortly.) This took a bit of time to
debate in the WG, so the document approval took a bit longer than
originally expected.

Best Regards,
Alexey, as the responsible AD