Use the same hard-coded fields for vlv-based autocompletion as in ste…

…ps/mail/autocomplete.inc

program/include/rcube_ldap.php

@@ -767,7 +767,7 @@ function search($fields, $value, $mode=0, $select=true, $nocount=false, $require
         }
 
         // use VLV pseudo-search for autocompletion
-        if ($this->prop['vlv_search'] && $this->conn && join(',', (array)$fields) == 'email,name')
+        if ($this->prop['vlv_search'] && $this->conn && join(',', (array)$fields) == 'name,firstname,surname,email')
         {
             // add general filter to query
             if (!empty($this->prop['filter']) && empty($this->filter))