lib/neutron: Remove type_driver configuration

Instead, rely on what Neutron ships by default.

Change-Id: I8bdc646d24b3edf10f421e4472a790caeb8e4887
diff --git a/lib/neutron b/lib/neutron
index d30e185..4915dcc 100644
--- a/lib/neutron
+++ b/lib/neutron
@@ -159,7 +159,6 @@
         # Configure VXLAN
         # TODO(sc68cal) not hardcode?
         iniset $NEUTRON_CORE_PLUGIN_CONF ml2 tenant_network_types vxlan
-        iniset $NEUTRON_CORE_PLUGIN_CONF ml2 type_drivers vxlan
         iniset $NEUTRON_CORE_PLUGIN_CONF ml2 mechanism_drivers openvswitch,linuxbridge
         iniset $NEUTRON_CORE_PLUGIN_CONF ml2_type_vxlan vni_ranges 1001:2000
         if [[ "$NEUTRON_PORT_SECURITY" = "True" ]]; then