chore: adjust rpc comment format (#2501)

tools/goctl/rpc/parser/comment.go

@@ -1,11 +1,15 @@
 package parser
 
-import "github.com/emicklei/proto"
+import (
+	"strings"
+
+	"github.com/emicklei/proto"
+)
 
 // GetComment returns content with prefix //
 func GetComment(comment *proto.Comment) string {
 	if comment == nil {
 		return ""
 	}
-	return "// " + comment.Message()
+	return "// " + strings.TrimSpace(comment.Message())
 }