Start Chat displays no error when feature-not-implemented result
The error dialog shows nothing when the server returns
<iq xmlns="jabber:client" from="janedoe1%irc.libera.chat@irc.jabberfr.org" xml:lang="en" type="error" to="lovetox@jabber.fr/gajim.OQITOMR5" id="c06171c8-9f42-4264-ba36-e60e9200ec98">
<error type="cancel">
<feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas" />
</error>
</iq>