[sonic-snmpagent] Update submodule (#13806)

#### Why I did it
Include below commits:
```
4622b8d 2023-02-14 | Fix: zero route may have empty nexthop (#276) [Qi Luo]
```
This commit is contained in:
Qi Luo 2023-02-15 14:15:52 -08:00 committed by GitHub
parent 5ce1b8e4b7
commit 373f0919e9
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@ -1 +1 @@
Subproject commit 4f55473f4af1115d86feb1a9ed3ab48dee75d8f8
Subproject commit 4622b8df01e6cfa818568b5a78a1a56ab555097d