解决panic: proto: duplicate enum registered: raftpb.EntryType

 报错信息：

A future release will panic on registration conflicts. See:
https://developers.google.com/protocol-buffers/docs/reference/go/faq#namespace-conflict

panic: proto: duplicate enum registered: raftpb.EntryType

goroutine 1 [running]:
github.com/golang/protobuf/proto.RegisterEnum(0x2461722, 0x10, 0xc0002b29f0, 0xc0002b2a20)
	/user/local/gopath/pkg/mod/github.com/golang/protobuf@v1.4.3/proto/registry.go:104 +0x11f
github.com/coreos/etcd/raft/raftpb.init.0()
	/user/local/gopath/pkg/mod/github.com/coreos/etcd@v3.3.18+incompatible/raft/raftpb/raft.pb.go:508 +0x52
make: *** [show] 错误 2

解决方法：go.mod中添加

replace go.etcd.io/etcd => github.com/coreos/etcd v3.3.10+incompatible