fix: operation http constant name conflict (#2087)

* add http operation const

* fix conflict name constant operation

cmd/protoc-gen-go-http/template.go

@@ -11,7 +11,7 @@ var httpTemplate = `
 {{$svrName := .ServiceName}}
 
 {{- range .Methods}}
-const Operation{{.OriginalName}} = "/{{$svrName}}/{{.OriginalName}}"
+const Operation{{$svrType}}{{.OriginalName}} = "/{{$svrName}}/{{.OriginalName}}"
 {{- end}}
 
 type {{.ServiceType}}HTTPServer interface {
@@ -51,7 +51,7 @@ func _{{$svrType}}_{{.Name}}{{.Num}}_HTTP_Handler(srv {{$svrType}}HTTPServer) fu
 			return err
 		}
 		{{- end}}
-		http.SetOperation(ctx,Operation{{.OriginalName}})
+		http.SetOperation(ctx,Operation{{$svrType}}{{.OriginalName}})
 		h := ctx.Middleware(func(ctx context.Context, req interface{}) (interface{}, error) {
 			return srv.{{.Name}}(ctx, req.(*{{.Request}}))
 		})
@@ -84,7 +84,7 @@ func (c *{{$svrType}}HTTPClientImpl) {{.Name}}(ctx context.Context, in *{{.Reque
 	var out {{.Reply}}
 	pattern := "{{.Path}}"
 	path := binding.EncodeURL(pattern, in, {{not .HasBody}})
-	opts = append(opts, http.Operation(Operation{{.OriginalName}}))
+	opts = append(opts, http.Operation(Operation{{$svrType}}{{.OriginalName}}))
 	opts = append(opts, http.PathTemplate(pattern))
 	{{if .HasBody -}}
 	err := c.cc.Invoke(ctx, "{{.Method}}", path, in{{.Body}}, &out{{.ResponseBody}}, opts...)