pimd: Allow v6 to do non-integrated configuration

pimd: Allow v6 to do non-integrated configuration

Proof:
eva# conf
eva(config)# no service integrated-vtysh-config
eva(config)# end
eva# wr mem
Note: this version of vtysh never writes vtysh.conf
Building Configuration...
Configuration saved to /etc/frr/zebra.conf
Configuration saved to /etc/frr/ripd.conf
Configuration saved to /etc/frr/ripngd.conf
Configuration saved to /etc/frr/ospfd.conf
Configuration saved to /etc/frr/ospf6d.conf
Configuration saved to /etc/frr/bgpd.conf
Configuration saved to /etc/frr/isisd.conf
Configuration saved to /etc/frr/pimd.conf
Configuration saved to /etc/frr/nhrpd.conf
Configuration saved to /etc/frr/eigrpd.conf
Configuration saved to /etc/frr/babeld.conf
Configuration saved to /etc/frr/sharpd.conf
Configuration saved to /etc/frr/fabricd.conf
Configuration saved to /etc/frr/pbrd.conf
Configuration saved to /etc/frr/staticd.conf
Configuration saved to /etc/frr/bfdd.conf
Configuration saved to /etc/frr/vrrpd.conf
Configuration saved to /etc/frr/pim6d.conf
eva#

Fixes: #12011
Signed-off-by: Donald Sharp <sharpd@nvidia.com>