Use sudo -e to edit gitlab.rb

If you editor writes configuration or history files it is annoying to
use `sudo edit`, because some of the configuration files for the current
user may end up being owned by root. Using `sudo -e` avoids this
problem.

source/downloads/index.html

@@ -73,7 +73,7 @@ platforms:
             <div class="tab-step">
               <p>Edit the configuration file to add your hostname</p>
               <p>
-                <pre>sudo edit /etc/gitlab/gitlab.rb</pre>
+                <pre>sudo -e /etc/gitlab/gitlab.rb</pre>
               </p>
             </div>