Fixed double-space typo.
diff --git a/user_guide/installation/upgrade_131.html b/user_guide/installation/upgrade_131.html
index 7541a83..a7025f2 100644
--- a/user_guide/installation/upgrade_131.html
+++ b/user_guide/installation/upgrade_131.html
@@ -57,7 +57,7 @@
<h1>Upgrading from 1.3 to 1.3.1</h1>
-<p class="important"><strong>Note:</strong> The instructions on this page assume you are running version 1.3. If you
+<p class="important"><strong>Note:</strong> The instructions on this page assume you are running version 1.3. If you
have not upgraded to that version please do so first.</p>
<p>Before performing an update you should take your site offline by replacing the index.php file with a static one.</p>