bridge: Increase IGMP/MLD robustness parameter to three for br-client

We are mostly dealing with the 2.4GHz crap-band here, so increasing the
IGMP/MLD robustness parameter to three to be able to compensate for up
to two consecutive instead of just one lost packet.

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

package/gluon-mesh-batman-adv-core/files/lib/gluon/upgrade/310-gluon-mesh-batman-adv-core-mesh

@@ -39,6 +39,7 @@ end
 uci:set('network', 'client', 'proto', 'dhcpv6')
 uci:set('network', 'client', 'reqprefix', 'no')
 uci:set('network', 'client', 'igmp_snooping', 0)
+uci:set('network', 'client', 'robustness', 3)
 uci:set('network', 'client', 'query_interval', 2000)
 uci:set('network', 'client', 'query_response_interval', 500)
 uci:set('network', 'client', 'peerdns', 1)