Crashes on second login attempt

Fractal Next crashes when the first login attempts fails and you try again.

Steps to reproduce:

1. Open Fractal Next
2. Try to login, but use an erroneous domain/user name
3. Login fails
4. Try to login again (doesn't matter whether credentials are correct or incorrect)

• This bug is reproducible from the latest nightly build of Fractal Next

Fractal Version: 3dea9a33

OS Version: Debian GNU/Linux 11 (bookworm/sid)

Installation Source: GitLab CI asset

Homeserver: (doesn't matter)

Crash report:

(fractal:2): Gtk-WARNING **: 18:51:09.043: GtkText - did not receive a focus-out event.
If you handle this event, you must return
GDK_EVENT_PROPAGATE so the default handler
gets the event as well
Oct 28 18:51:09.839 ERROR fractal::session: Failed to prepare the session: error sending request for url (https://domain.tld/_matrix/client/r0/login): error trying to connect: dns error: failed to lookup address information: Name or service not known    
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: EnterError', /run/build/fractal/_flatpak_build/cargo-home/registry/src/github.com-1ecc6299db9ec823/glib-0.14.8/src/main_context_futures.rs:201:52
stack backtrace:
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Couldn't figure out how to get the full backtrace, but it seems very easy to reproduce.