Typo: Bad time_or_node Reference in Section 4.5.4

[nerg4l]

Sequence 4.5.4 references time_or_node multiple times.

Examples:

   10.  Format by concatenating the 128-bits as: timestamp_32|timestamp_
        48|version|time_or_node|variant|seq_or_node|node

   6.   Set 12-bit time_or_node to the 12 least significant bits from
        the timestamp

Section 4.5 only describes time_or_seq and every other section under Section 4.5 only references time_or_seq.