core/calendar: Remove connection timeout

As per discussions, this is not really what we want here. There
already is offline caching and post-connection sync, so we want
to show events as soon as possible.

Closes https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/1027
Closes https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/569

src/core/gcal-calendar.c

@@ -198,10 +198,9 @@ gcal_calendar_initable_init (GInitable     *initable,
                                                     G_CALLBACK (on_source_name_changed_cb),
                                                     self);
 
-  /* 15s is arbitrary, but very rarely this will be reached */
   client = e_cal_client_connect_sync (priv->source,
                                       E_CAL_CLIENT_SOURCE_TYPE_EVENTS,
-                                      15,
+                                      (guint32) -1,
                                       cancellable,
                                       &local_error);