Fix default keyservers (use keys.openpgp.org), add note about CORS (#7373, #7367)

CHANGELOG

@@ -5,6 +5,7 @@ CHANGELOG Roundcube Webmail
 - Fix so the database setup description is compatible with MySQL 8 (#7340)
 - Markasjunk: Fix regression in jsevent driver (#7361)
 - Fix missing flag indication on collapsed thread in Larry and Elastic (#7366)
+- Fix default keyservers (use keys.openpgp.org), add note about CORS (#7373, #7367)
 
 RELEASE 1.4.4
 -------------

config/defaults.inc.php

@@ -841,8 +841,8 @@ $config['compose_responses_static'] = array(
 );
 
 // List of HKP key servers for PGP public key lookups in Enigma/Mailvelope
-// Default: array("keys.fedoraproject.org", "keybase.io")
+// Note: Lookup is client-side, so the server must support Cross-Origin Resource Sharing
-$config['keyservers'] = array();
+$config['keyservers'] = array('keys.openpgp.org');
 
 // ----------------------------------
 // ADDRESSBOOK SETTINGS