Reference v6.3.1 in the downloads page

Change-Id: I6b3f8238401afd10673527ace9b06ce3b1c68fd5
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>
diff --git a/download.html b/download.html
index 8d5c645..b6f9cec 100644
--- a/download.html
+++ b/download.html
@@ -143,8 +143,8 @@
 			
 							<h3>Latest Release</h3>
 							<p>Add this URL to your Eclipse Installation to reach Sirius Update Site.</p>
-							<input type="text" value="http://download.eclipse.org/sirius/updates/releases/6.3.0/2019-06" />
-							<p>You can also download the corresponding <a href="http://download.eclipse.org/sirius/updates/releases/6.3.0/org.eclipse.sirius-6.3.0-2019-06.zip">zipped archive</a> for offline installation.</p>
+							<input type="text" value="http://download.eclipse.org/sirius/updates/releases/6.3.1/2019-06" />
+							<p>You can also download the corresponding <a href="http://download.eclipse.org/sirius/updates/releases/6.3.1/org.eclipse.sirius-6.3.1-2019-06.zip">zipped archive</a> for offline installation.</p>
 							<br />
 
 							<h3>Latest Nightly</h3>