[sonic-snmpagent][sonic-py-swsssdk] Update submodules (sonic-net#4968)

* src/sonic-snmpagent 89b7b2c...c702a57 (7):
  > Revert "[rfc1213] Interface MIB add l3 vlan interfaces & aggregate rif counters (sonic-net#133)" (sonic-net#151)
  > Update transceiver info DB key names (sonic-net#146)
  > Fix LGTM reported alert of PR#141 (sonic-net#142)
  > [Namespace] Fix interfaces counters in InterfacesMIB RFC 2863 (sonic-net#141)
  > [Namespace]: Fix SNMP AgentX  socket connection timeout when using Namespace.get_all()  (sonic-net#140)
  > [rfc1213] Interface MIB add l3 vlan interfaces & aggregate rif counters (sonic-net#133)
  > Fix undefined variable and warning message (sonic-net#134)

* src/sonic-py-swsssdk a83366e...2df4f40 (3):
  > Allowing TCP connections with namespace as well. (zhenggen-xu#81)
  > [port_util] add get_rif_port_map, get_vlan_interface_oid_map (zhenggen-xu#78)
  > Updates to the namespace API's for test_moduleLoad.py (zhenggen-xu#77)

Note that sonic-snmpagent submodule update is dependent upon sonic-py-swsssdk update, so updating both submodules in this PR.