Invalid URN representation of SMPTE ULs

The following URN representation of a SMPTE UL is invalid:

`urn:smpte:ul:06.0E.2B.34.04.01.01.0D.04.01.01.01.01.0A.00.00`

It should instead be:

`urn:smpte:ul:060E2B34.0401010D.04010101.010A0000`

according to SMPTE ST 2029.
