Fx60: Fix access to translator object in sandbox

There's almost certainly other sandbox breakage

chrome/content/zotero/xpcom/translation/translate.js

@@ -313,16 +313,6 @@ Zotero.Translate.Sandbox = {
 			 * @inner
 			 */
 			var safeTranslator = {};
-			safeTranslator.__exposedProps__ = {
-				"setSearch":"r",
-				"setDocument":"r",
-				"setHandler":"r",
-				"setString":"r",
-				"setTranslator":"r",
-				"getTranslators":"r",
-				"translate":"r",
-				"getTranslatorObject":"r"
-			};
 			safeTranslator.setSearch = function(arg) {
 				if(!Zotero.isBookmarklet) arg = JSON.parse(JSON.stringify(arg));
 				return translation.setSearch(arg);