Merging (my) pull request #30 (from p-l/scapy/issue5081), because that's a...

Merging (my) pull request #30 (from p-l/scapy/issue5081), because that's a tiny patch that's hardly going to add new troubles, plus @chrisjameskirkham (who initialy reported #5081) validated this fixes the issue.

Changed registration order for CookedLinux layer 2 type (fixes #5081)