ssl: fix segfault when using SSL_CTX that is not created
ssl: fix segfault when using SSL_CTX that is not created

vhost->ssl_ctx is created in 'lws_tls_server_vhost_backend_init', but it
is used before in 'lws_tls_server_client_cert_verify_config' when
calling SSL_CTX_set_session_id_context...

Signed-off-by: Petar Paradzik <834935bddfbc2facb237e79a824da20875606b7d@sartura.hr>

sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets