style: using is struct to handle all judgements global envs

handlers.go

@@ -54,7 +54,7 @@ func Auth(w http.ResponseWriter, r *http.Request, targetMethod string, allowedUs
 		return 0, fmt.Errorf("Method not allowed: %s", targetMethod)
 	}
 
-	if !isDebug && !ValidateTimeStamp(r.Header) {
+	if !is.debug && !ValidateTimeStamp(r.Header) {
 		return 0, fmt.Errorf("Invalid or missing X-Timestamp in header")
 	}