Fixed typo in delete_post_modal

web/react/components/delete_post_modal.jsx

@@ -98,7 +98,7 @@ module.exports = React.createClass({
                     : "" }
                   </div>
                   <div className="modal-footer">
-                    <button type="button" className="btn btn-default" data-dismiss="modal">Close</button>
+                    <button type="button" className="btn btn-default" data-dismiss="modal">Cancel</button>
                     <button type="button" className="btn btn-danger" data-dismiss="modal" onClick={this.handleDelete}>Delete</button>
                   </div>
                 </div>