Huawei openUBMC low-privilege SNMP to administrator privilege escalation

openUBMC assigns the full privilege set to pseudo-identities representing SNMP callers. An authenticated, but low-privilege, SNMP user can therefore invoke mapped backend operations as an administrative identity. In `route_mapper/account.lua`, `get_user_privilege` returns the complete nine-privilege set for a `special_users` group that includes the `SNMPv1_v2c` pseudo-user.