ui: remove 'enabled' and 'ws_enabled' fields from VncState

The 'ws_enabled' field is never used outside of the
vnc_display_open method, so can be a local variable.

The 'enabled' field is easily replaced by a check
for whether 'lsock' is non-NULL.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-3-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
