Snmpd.init Missing Extend

Hi,

Checking out the file in the repository, https://github.com/openwrt/packages/blob/master/net/net-snmp/files/snmpd.init ... it seems that the correction to provide extend support is missing in v18.06 (even v18.06.4 recently) - is there a reason it's not included?

As extend is being used to replace exec, it would be nice to have this capability.

Thanks!