Fix generation robot link of Poppy Ergo jr

Author: show0k

_pages/robots/ergo/en.html

@@ -61,7 +61,7 @@ <h2>Program Ergo Jr</h2>
 <div class="text-center">
   <h2>Get your Ergo Jr</h2>
 
-  <a href="http://www.generationrobots.com/fr/328-robot-poppy-ergo-jr" class="button success large">Order your Ergo Jr</a><br>
+  <a href="http://www.generationrobots.com/en/328-robot-poppy-ergo-jr" class="button success large">Order your Ergo Jr</a><br>
   <a href="https://github.com/poppy-project/poppy-ergo-jr" class="button">Browse the source files</a>
 
 </div>