fix ios smscode

@@ -55,7 +55,9 @@ export default {
         let half = newVal.length / 2;
 
         if (newVal.substring(0, half) === newVal.substring(half)) {
-          this.smsCode = newVal.substring(0, half);
+          setTimeout(() => {
+            this.smsCode = newVal.substring(0, half);
+          }, 0);
         }
       }
     }