docs/website: download.html: correct version number in title

Fixes #11716

Latest release is 2019.02.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 964d525970e8d6dfd7807dc965d07e0d2bcc49f7)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

docs/website/download.html

@@ -8,7 +8,7 @@
     <div class="panel-heading">Download</div>
     <div class="panel-body">
 
-      <h3 style="text-align: center;">Latest stable / long term support release: <b>2018.02.11</b></h3>
+      <h3 style="text-align: center;">Latest stable / long term support release: <b>2019.02</b></h3>
 
       <div class="row mt centered">
 	<div class="col-sm-6">