DH group 15 was not selectable in the UI, and I strongly suspect this
patch will fix that, as that particular choices was missing in
`choices.py`.
Signed-off-by: Jorik Jonker <jorik@kippendief.biz>
Fixes#14793
* Move L2VPN and L2VPNTermination models from ipam to vpn
* Move L2VPN resources from ipam to vpn
* Extend migration to update content types
* Misc cleanup
- Introduces a new `vpn` app with the following models:
- Tunnel
- TunnelTermination
- IKEProposal
- IKEPolicy
- IPSecProposal
- IPSecPolicy
- IPSecProfile
