gluon-mesh-batman-adv: reenable batman-adv multicast optimizations

Several fixes and enhancements related to multicast were added upstream
in batman-adv. So let's give the batman-adv multicast optimizations
another go.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>

package/gluon-mesh-batman-adv/luasrc/lib/gluon/upgrade/310-gluon-mesh-batman-adv-mesh

@@ -19,7 +19,7 @@ uci:section('batman-adv', 'mesh', 'bat0', {
 	gw_sel_class = gw_sel_class,
 	hop_penalty = 15,
 	routing_algo = routing_algo,
-	multicast_mode = false,
+	multicast_mode = true,
 })
 uci:save('batman-adv')