Fix substitution for nbsp

We were substituting the wrong character for non-breaking spaces

boot/boot.js

@@ -201,7 +201,7 @@ $tw.utils.deepDefaults = function(object /*, sourceObjectList */) {
 Convert "&amp;" to &, "&nbsp;" to nbsp, "&lt;" to <, "&gt;" to > and "&quot;" to "
 */
 $tw.utils.htmlDecode = function(s) {
-	return s.toString().replace(/&lt;/mg,"<").replace(/&nbsp;/mg,"\x40").replace(/&gt;/mg,">").replace(/&quot;/mg,"\"").replace(/&amp;/mg,"&");
+	return s.toString().replace(/&lt;/mg,"<").replace(/&nbsp;/mg,"\xA0").replace(/&gt;/mg,">").replace(/&quot;/mg,"\"").replace(/&amp;/mg,"&");
 };
 
 /*