Update Download.html

remove a statement about stable release.

Author: wkliao

wiki/Download.html

@@ -42,8 +42,6 @@
 <center> <h2>PnetCDF Source Code Downloads</h2> </center>
 <br>
 
-The latest stable release of <a href="../index.html">PnetCDF</a> is version 1.13.0.
-<p>
 We encourage PnetCDF users to use the latest released version. If for some
 reason you would like to try out older versions, below is a table of (most of)
 our historical releases and their release notes.  <p>