fix typo

lib/imap.js

@@ -335,7 +335,7 @@ ImapConnection.prototype.connect = function(loginCb) {
             parsers.parseFetch(m.info, indata.literals, details);
             details.seqno = parseInt(m.num, 10);
 
-            if (typeof details['x-gm-labels'] !== undefined) {
+            if (details['x-gm-labels'] !== undefined) {
               var labels = details['x-gm-labels'];
               for (var i=0, len=labels.length; i<len; ++i)
                 labels[i] = labels[i].replace(RE_ESCAPE, '\\');