fix: dropdown disabled not work #1400

Author: tangjinzhou

components/dropdown/dropdown.jsx

@@ -81,7 +81,9 @@ const Dropdown = {
 
     const dropdownTrigger = cloneElement($slots.default, {
       class: `${prefixCls}-trigger`,
-      disabled,
+      props: {
+        disabled,
+      },
     });
     const triggerActions = disabled ? [] : trigger;
     let alignPoint;

components/vc-dropdown/src/Dropdown.jsx

@@ -1,4 +1,3 @@
-import classNames from 'classnames';
 import PropTypes from '../../_util/vue-types';
 import Trigger from '../../vc-trigger';
 import placements from './placements';