fix: remove useless proto calls in gossip

packages/gossip/events.go

packages/gossip/manager.go

packages/gossip/manager_test.go

packages/gossip/proto/message.pb.go

packages/gossip/proto/message.proto

packages/transactionspammer/transactionspammer.go

plugins/gossip/gossip.go

plugins/gossip/plugin.go

plugins/tangle/solidifier.go

plugins/tangle/solidifier_test.go

plugins/webapi-send-data/plugin.go