Update 13.html

wrong link in tutorial

Author: borismarin

NeuroML2/osbSessions/13.html

@@ -5,7 +5,7 @@
     <p>You can rerun these experiments, changing the input stimuli or cell properties. 
         However <strong>you need to be registered on OSB and logged in</strong>.</p>
 
-    <p>To register as a new OSB user, please go <a href="https://neuron.yale.edu/neuron/" target="_blank">here</a>.</p>
+    <p>To register as a new OSB user, please go <a href="http://opensourcebrain.org/account/register" target="_blank">here</a>.</p>
 
     <p>If you are not logged in already, you will need to refresh this tutorial once you are to continue with running simulations.</p>