PoM transaction is accepted but the pomHeights is not updated for an account in the DB

[ishantiw]

Expected behavior

When we receive a valid PoM transaction then it should be accepted and update the pomHeights field of the reported delegate

Actual behavior

It was not updating pomHeights of the reported delegate and hence it was not getting punished and you can re-submit the same pom trx again and again.

Steps to reproduce

1. Create a pom trx
2. Broadcast the trx
3. Check if the pomHeights value is updated for the reported delegate

Which version(s) does this affect? (Environment, OS, etc...)

4.0.0