Fixed copyright date and removed debug code from AutosizeTextarea (#4457)

webapp/components/autosize_textarea.jsx

@@ -1,4 +1,4 @@
-// Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
 // See License.txt for license information.
 
 import React from 'react';
@@ -53,7 +53,6 @@ export default class AutosizeTextarea extends React.Component {
     }
 
     render() {
-        window.forceUpdate = this.forceUpdate.bind(this);
         const {
             value,
             placeholder,