GUACAMOLE-313: Properly initialize modifier flag for all keydefs.
GUACAMOLE-313: Properly initialize modifier flag for all keydefs.

apache/guacamole-server,apache/guacamole-server,glyptodon/guacamole-server,mike-jumper/incubator-guacamole-server,glyptodon/guacamole-server,glyptodon/guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server