Issue: Incorrect offset in sample -tls

[slightlyfloating]

I believe the sample given in https://tools.ietf.org/html/draft-ietf-quic-tls-24#appendix-A.2
contains an incorrect offset to the packet number field,

Considering the 22-byte long header given in the sample
c3 ff000017 08 8394c8f03e515708 00 00 449e 00000002
I think the following line
header[17..20] ^= mask[1..4]
is supposed to read:
header[18..21] ^= mask[1..4]
as the 4-byte packet number (0x00000002) actually starts at offset 18 (0-based) of the header.