This patch adds a simple check to silence logging of messages about
unrecognized igmp packets which originate from devices in local network.
Without this patch igmpproxy floods openwrt syslog with messages such as:
user.warn igmpproxy[19818]: The source address 192.168.1.175 for group
239.255.250.250, is not in any valid net for upstream VIF.
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
SVN-Revision: 44020
