[BUG] Idempotency when receiving the answer to a query that has already been answered

[MariemBaccari]

Description (Actual behavior)

Currently, when we receive the answer to a query twice, we return an error to the peer the second time.

Expected behavior

This is not useful since the peers only log the errors they receive and we don't expect anything in return. It is enough to log it.

How to reproduce

This issue was first discussed in #1694

Front-ends:

• Fe1-Web (please include browser's names & version)
• Fe2-Android (please specify if phone or emulation, and Android version)
• Not applicable

Back-ends:

• Be1-Go
• Be2-Scala
• Not applicable

Impact

This doesn't cause any issue, at least between two go servers, as they just log the errors that they receive.

Possible root cause

The error originates from the Queries.go SetQueryReceived function and propagates all the way to the socket. We should log the error instead of sending it back.