zebra: Don't install connected routes multiple times into FRR

zebra: Don't install connected routes multiple times into FRR

When moving an interface between vrf's we do not need
to install the connected routes multiple times.

eva# show ip route vrf all
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

VRF BLUE:
C>* 4.5.6.7/32 is directly connected, dummy7, 00:00:10

VRF default:
K>* 0.0.0.0/0 [0/100] via 192.168.119.1, enp39s0, 00:00:10
C>* 192.168.119.0/24 is directly connected, enp39s0, 00:00:10
eva# exit
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> sudo ip link add GREEN type vrf table 11000
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> sudo ip link set GREEN up
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> sudo ip link set dummy7 master GREEN
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> vtysh

Hello, this is FRRouting (version 8.4-dev).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

eva# show ip route vrf all
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

VRF GREEN:
C>* 4.5.6.7/32 is directly connected, dummy7, 00:00:05

VRF default:
K>* 0.0.0.0/0 [0/100] via 192.168.119.1, enp39s0, 00:01:03
C>* 192.168.119.0/24 is directly connected, enp39s0, 00:01:03
eva# exit
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> sudo ip link set dummy7 nomaster
sharpd@eva ~/f/t/topotests (multiple_connected_installs)> sudo vtysh -c "show ip route vrf all"
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

VRF default:
K>* 0.0.0.0/0 [0/100] via 192.168.119.1, enp39s0, 00:03:22
C>* 4.5.6.7/32 is directly connected, dummy7, 00:00:08
C>* 192.168.119.0/24 is directly connected, enp39s0, 00:03:22
sharpd@eva ~/f/t/topotests (multiple_connected_installs)>
 @  11 0:-*                                                                                                                                                         5h50m 0.06 24x1.9GHz 31.4G26% 426G70% 2022-08-08 13:49:24

Signed-off-by: Donald Sharp <sharpd@nvidia.com>