fix format detection where vyos was overriding flat juniper
fix format detection where vyos was overriding flat juniper

dhalperi/batfish,dhalperi/batfish,intentionet/batfish,batfish/batfish,arifogel/batfish,intentionet/batfish,batfish/batfish,dhalperi/batfish,arifogel/batfish,intentionet/batfish,batfish/batfish,intentionet/batfish,intentionet/batfish,arifogel/batfish