snmp: T1921: reduce syslog noise
snmp: T1921: reduce syslog noise

Remove informative but noisy messages:
Dec 30 11:45:02 vyos snmpd[2870]: Connection from UDP: [172.16.100.1]:42781 ...
Dec 30 11:45:02 vyos snmpd[2870]: Connection from UDP: [172.16.100.1]:57331 ...

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x