VPP crashes if using VPP/non-VPP interfaces for OSPF MPLS
Topology
{F11329123}
The `wan-vpp` configuration:
```
set interfaces ethernet eth0 address '10.0.0.254/24'
set interfaces ethernet eth0 description 'Switch1'
set interfaces ethernet eth1 address '10.0.1.1/30'
set interfaces ethernet eth1 description 'Link-to-wan-right'
set interfaces ethernet eth2 address '10.0.4.1/30'
set interfaces ethernet eth2 description 'r4'
set interfaces loopback lo
set protocols mpls interface 'eth0'
set protocols mpls interface 'eth1'
set protocols mpls interface 'eth2'
set protocols mpls ldp discovery transport-ipv4-address '100.64.0.254'
set protocols mpls ldp interface 'eth0'
set protocols mpls ldp interface 'lo'
set protocols mpls ldp interface 'eth1'
set protocols mpls ldp interface 'eth2'
set protocols mpls ldp router-id '100.64.0.254'
set protocols ospf interface eth0 area '0'
set protocols ospf interface eth1 area '0'
set protocols ospf interface eth2 area '0'
set protocols ospf interface vpptun0 area '0'
set system host-name 'wan-vpp'
set system login user vyos authentication plaintext-password ''
set vpp interfaces loopback lo0 kernel-interface 'vpptun0'
set vpp kernel-interfaces vpptun0 address '100.64.0.254/32'
set vpp settings interface eth0 driver 'dpdk'
set vpp settings interface eth1 driver 'dpdk'
set vpp settings unix poll-sleep-usec '120'
```
The interface `eth2` on the `wan-vpp` node is a regular I interface (without VPP)
After loading OSPF and state `full`, we have VPP crash (interfaces eth0/eth1) disappears from the system
```
vyos@wan-vpp:~$ show int
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address MAC VRF MTU S/L Description
----------- ------------- ----------------- ------- ----- ----- -----------------
eth0 10.0.0.254/24 0c:65:9d:44:00:00 default 1500 u/D Switch1
eth1 10.0.1.1/30 0c:65:9d:44:00:01 default 1500 u/D Link-to-wan-right
eth2 10.0.4.1/30 0c:65:9d:44:00:02 default 1500 u/u r4
eth3 - 0c:65:9d:44:00:03 default 1500 u/D
eth4 - 0c:65:9d:44:00:04 default 1500 u/D
lo 127.0.0.1/8 00:00:00:00:00:00 default 65536 u/u
::1/128
vyos@wan-vpp:~$
vyos@wan-vpp:~$ show ip ospf neighbor
Neighbor ID Pri State Up Time Dead Time Address Interface RXmtL RqstL DBsmL
100.64.0.4 1 Loading/DR 2.745s 30.902s 10.0.4.2 eth2:10.0.4.1 0 1 0
vyos@wan-vpp:~$
vyos@wan-vpp:~$
vyos@wan-vpp:~$ show ip ospf neighbor
Neighbor ID Pri State Up Time Dead Time Address Interface RXmtL RqstL DBsmL
100.64.0.4 1 Full/DR 3.831s 34.816s 10.0.4.2 eth2:10.0.4.1 1 0 0
vyos@wan-vpp:~$
vyos@wan-vpp:~$
vyos@wan-vpp:~$ show ip ospf neighbor
Neighbor ID Pri State Up Time Dead Time Address Interface RXmtL RqstL DBsmL
100.64.0.4 1 Full/DR 7.489s 31.158s 10.0.4.2 eth2:10.0.4.1 0 0 0
vyos@wan-vpp:~$
vyos@wan-vpp:~$ show int
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address MAC VRF MTU S/L Description
----------- ------------ ----------------- ------- ----- ----- -------------
eth2 10.0.4.1/30 0c:65:9d:44:00:02 default 1500 u/u r4
eth3 - 0c:65:9d:44:00:03 default 1500 u/D
eth4 - 0c:65:9d:44:00:04 default 1500 u/D
lo 127.0.0.1/8 00:00:00:00:00:00 default 65536 u/u
::1/128
vyos@wan-vpp:~$
```