fix animation is null, tween not remove

Author: jljsj33

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rc-tween-one",
-  "version": "2.2.16",
+  "version": "2.2.17",
   "description": "tween-one anim component for react",
   "keywords": [
     "react",

src/TweenOne.jsx

@@ -202,6 +202,8 @@ class TweenOne extends Component {
       this.raf();
       // 开始动画
       this.play();
+    } else {
+      this.tween = null;
     }
   }
 
@@ -250,7 +252,7 @@ class TweenOne extends Component {
         ...e,
         timelineMode: '',
       };
-      
+
       if (
         (this.moment === this.startMoment &&
           (!this.reverse && !e.index && e.mode === 'onStart') ||