fix JS warnings

chrome/content/zotero/overlay.js

@@ -1566,6 +1566,7 @@ var ZoteroPane = new function()
 				}
 				
 				if (item.isAttachment()) {
+					var showSep4 = false;
 					hide.push(m.duplicateItem);
 					// If not linked URL, show reindex line
 					if (Zotero.Fulltext.canReindex(item.id)) {

chrome/content/zotero/recognizePDF.js

@@ -29,7 +29,7 @@ const MAX_PAGES = 2;
  * Front end for recognizing PDFs
  * @namespace
  */
-Zotero_RecognizePDF = new function() {
+var Zotero_RecognizePDF = new function() {
 	/**
 	 * Checks whether a given PDF could theoretically be recognized
 	 * @returns {Boolean} True if the PDF can be recognized, false if it cannot be