Removing XMPP component mode

As we mentioned on the community call earlier today, we will be removing the ability of jitsi-videobridge to connect as an XMPP server component.

The feature has been deprecated for a while in favor of connecting as an XMPP user and advertising presence in a MUC. Our debian packages and docker images have been using the new mode for a few months now.

If you are still using the component mode, you should migrate to the MUC mode. The required configuration is described here: https://github.com/jitsi/jitsi-videobridge/blob/master/doc/muc.md

Boris