[sonic-snmpagent]: Advance submodule (#8176)

qiluo-msft · web-flow · commit 30e9c0e7d3e5 · 2021-07-14T00:07:15.000-07:00
Includes below commits ``` 946e5cf 2021-07-12 | Fix: SonicV2Connector behavior change: get_all will return empty dict if (#226) [Qi Luo] ```
diff --git a/src/sonic-snmpagent b/src/sonic-snmpagent
@@ -1 +1 @@
-Subproject commit 748b545f396f132b8decb206d2f6a5bcf5445cac
+Subproject commit 946e5cf2344da47d0cdf8de5d31d70b0484664ef
