fixed: issue with error loop in pipe code

so this code make error recurrung call and as the result stack overflow when come things wrong with connection lost connection or dns lookup failed

  var cleartext = pair.cleartext;
  cleartext.socket = socket;

  function onerror(e) {
    if (cleartext._controlReleased)
      cleartext.socket.emit('error', e);// in this line we call emit error event in recurring way. 
  }

  socket.on('error', onerror);// this code the same as cleartext.socket.on('error', onerror)

imap.js

@@ -1695,7 +1695,7 @@ function pipe(pair, socket) {
 
   function onerror(e) {
     if (cleartext._controlReleased)
-      cleartext.socket.emit('error', e);
+      cleartext.emit('error', e);
   }
 
   function onclose() {