Release v1.9.3.

Author: diasbruno

bower.json

@@ -1,6 +1,6 @@
 {
   "name": "react-modal",
-  "version": "1.9.2",
+  "version": "1.9.3",
   "homepage": "https://github.com/reactjs/react-modal",
   "authors": [
     "Ryan Florence",

dist/react-modal.js

@@ -154,6 +154,8 @@ return /******/ (function(modules) { // webpackBootstrap
 	  },
 
 	  componentWillUnmount: function componentWillUnmount() {
+	    if (!this.node) return;
+
 	    refCount.remove(this);
 
 	    if (this.props.ariaHideApp) {