fix: clear autoscroller when autoscroll is disabled (#604)

Author: superandrew213

src/AutoScroller/index.js

@@ -5,8 +5,10 @@ export default class AutoScroller {
   }
 
   clear() {
-    clearInterval(this.interval);
-    this.interval = null;
+    if (this.interval != null) {
+      clearInterval(this.interval);
+      this.interval = null;
+    }
   }
 
   update({translate, minTranslate, maxTranslate, width, height}) {

src/SortableContainer/index.js

@@ -827,6 +827,7 @@ export default function sortableContainer(
       const {isKeySorting} = this.manager;
 
       if (disableAutoscroll) {
+        this.autoScroller.clear();
         return;
       }