Fix flaky failures in client auth failure tests
Fix flaky failures in client auth failure tests

The test is currently too strict about which errors to expect after the
server drops the connection. It expects G_IO_ERROR_BROKEN_PIPE to only
occur during the close, but it could also occur during the read, in
which case there will be no error on close. It's a shame we can't
guarantee a consistent error in this case and the errors in general
could stand to be improved, but important thing is that there is some
error: the read is (properly) not working.

Fixes #66

GNOME/glib-networking,GNOME/glib-networking,GNOME/glib-networking