Update download link to link to nightly build update site

Change-Id: I2d1f0aa2b21eaebf42d00501da9e942d7f397998
Signed-off-by: Markus Duft <markus.duft@ssi-schaefer.com>
diff --git a/download.html b/download.html
index f403764..5600839 100644
--- a/download.html
+++ b/download.html
@@ -67,7 +67,7 @@
 				<h2>Eclipse Updatesites</h2>
 				<p>These sites can be used to install the TEA features into a running Eclipse. Currently no site is available (yet).</p>
 				<p><a href="#" class="has-popover btn btn-primary btn-medium disabled">Releases (right click &amp; copy)</a></p>
-				<p><a href="#" class="has-popover btn btn-primary btn-medium disabled">Nightly Builds (right click &amp; copy)</a></p>
+				<p><a href="http://download.eclipse.org/tea/nightly" class="has-popover btn btn-primary btn-medium">Nightly Builds (right click &amp; copy)</a></p>
 				<h3>Installation Instructions</h3>
 				<ul>
 					<li>Choose <e>Help -&gt; Install New Software...</e> from the menu bar and <e>Add...</e>.</li>