websocket support is available since version 4.3.3 and
9be8334938
It is enabled if --enable-drafts is passed by the user.
websocket can use libnss or gnutls instead of its builtin SHA1 since
7296fb5b15
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>