GUACAMOLE-1215: Add backslash to list of JSON-escaped characters.
GUACAMOLE-1215: Add backslash to list of JSON-escaped characters.

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