Fix GPL version

_layouts/default.html

@@ -54,7 +54,7 @@
     
         <div class="footer">
             <p>Printrun is free, open-source software. Dedicated to #reprap @ irc.freenode.net.<br />
-            Printrun is licensed under the GNU General Public License, version 2</p>
+            Printrun is licensed under the GNU General Public License, version 3</p>
         </div>
 
         <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>

index.html

@@ -197,7 +197,7 @@ layout: default
             <div id="about" class="separator bg-green"></div>
             <div class="container content about">
                 <h2 class="border-green">About</h2>
-                <p>Printrun is free, open-source software, licensed under the GNU General Public License, version 2.<br />
+                <p>Printrun is free, open-source software, licensed under the GNU General Public License, version 3.<br />
                 Printrun was created by <a href="https://0xfb.com/">Kliment Yanev</a>, and is now co-maintained by him and <a href="http://guillaume.segu.in/">Guillaume <em>"iXce"</em> Seguin</a>.<br />
                 Contributions are more than welcome, and have been received from:
                 </p>