GUACAMOLE-982: Merge fix the error log message when the creating thread of RDP client fails
GUACAMOLE-982: Merge fix the error log message when the creating thread of RDP client fails


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