bug: New PeerExchange protocol cannot decode correctly old rpc

[NagyZoltanPeter]

Problem

With v0.33.0-rc2 test we see, that new PeerExchange RPC is not decoded well when request coming from clients using protocol the old way.

Impact

Missing response field is identified as error in case of request RPC.

To reproduce

status.staging fleet testing v0.33.0-rc2 has thousands of this error, no PeerExchange is working there now.

Expected behavior

Response field shall not be handled as mandatory for requests.

Screenshots/logs

nwaku version/commit hash

v0.33.0-rc2

[NagyZoltanPeter]

Fixed with PR #3055
https://grafana.infra.status.im/d/qrp_ZCTGz/nim-waku-v2?var-host=.%2A&var-fleet=status.staging&var-dc=All
status.staging with v0.33.0-rc3 deployed now serving PX requests.