core (xmpp): avoid starting several clients at the same time: a check is done to avoid running startConnection several times at once, which would lead to the creation of several SatXMPPEntity instances at the same time, resulting in many issues. If startConnection is called while a previous one is not finished yet, a CancelError is now raised.

You'll find install instructions in documentation (see doc/installation.rst).

If you need help, come the SàT official XMPP room: sat@chat.jabberfr.org or join us with a web browser via https://chat.jabberfr.org/converse.js/sat@chat.jabberfr.org