Make freeports transparent

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@628 42af7a65-404d-4744-a932-0658087f49c3

Documentation/NuttXBanner.html

@@ -31,9 +31,9 @@
   </td>
   <td width="210">
     <a href="freeports.html" target="_blank">
-      <img src="freeports.jpg" width="210" height="62" border="0"/>
+      <img src="freeports.gif" width="210" height="62" border="0"/>
     </a>
   </td>
   </tr>
 </body>
-</html>
\ No newline at end of file
+</html>