Made the string that describes how long a key is valid for say that it's valid for 365 days.

It's now a %s based string, which means we can change the logic later and only have to update the lifetime in one place.

htdocs/admin/site/networking.php

@@ -68,7 +68,7 @@ $networkingform = pieform(
             'pubkey' => array(
                 'type'         => 'html',
                 'title'        => get_string('publickey','admin'),
-                'description'  => get_string('publickeydescription', 'admin'),
+                'description'  => get_string('publickeydescription2', 'admin', 365),
                 'value'        => '<pre style="font-size: 0.7em">'.$openssl->certificate.'</pre>'
             ),
             'expires' => array(

htdocs/lang/en.utf8/admin.php

@@ -188,7 +188,7 @@ $string['adminfilespagedescription'] = 'Here you can upload files that can be in
 // Networking options
 $string['networkingextensionsmissing'] = 'Sorry, you cannot configure Mahara networking because your PHP installation is missing one or more required extensions:';
 $string['publickey'] = 'Public key';
-$string['publickeydescription'] = 'This public key is automatically generated, and rotated every 28 days';
+$string['publickeydescription2'] = 'This public key is automatically generated, and rotated every %s days';
 $string['publickeyexpires'] = 'Public key expires';
 $string['enablenetworkingdescription'] = 'Allow your Mahara server to communicate with servers running Moodle and other applications';
 $string['enablenetworking'] = 'Enable networking';