Add Ftp ant task wakeUpTransferInterval documentation also updated

manual/Tasks/ftp.html

@@ -225,6 +225,13 @@ connection.</p>
       A value of 0 means an infinite timeout.<em>since Ant 1.10.7</em></td>
     <td>No</td>
   </tr>
+  <tr>
+    <td>wakeUpTransferInterval</td>
+    <td>Only use if proved to be necessary, interval in seconds on which a LIST command is triggered
+      trigger a data connection (to avoid timeouts by the ftp server on no data connection).
+      <em>since Ant 1.10.7</em></td>
+    <td>No</td>
+  </tr>
   <tr>
     <td colspan="3" class="left">
       <p><strong>The following attributes