wallet search fix

api/gateway/mntx/internal/service/gateway/metrics.go

@@ -164,11 +164,3 @@ func statusLabel(err error) string {
 		return "error"
 	}
 }
-
-func normalizeCallbackStatus(status string) string {
-	status = strings.TrimSpace(status)
-	if status == "" {
-		return "unknown"
-	}
-	return strings.ToLower(status)
-}