refactor: Fix Migration and program name

gajim/gtk/application.py

@@ -194,9 +194,7 @@ def __init__(self):
 
         self.interface = None
 
-        GLib.set_prgname(app.get_default_app_id())
-        if GLib.get_application_name() != 'Gajim':
-            GLib.set_application_name('Gajim')
+        GLib.set_application_name('Gajim')
 
     @staticmethod
     def _get_remaining_entry():

gajim/gtk/db_migration.py

@@ -9,6 +9,7 @@
 from io import StringIO
 
 from gi.repository import Gtk
+from gi.repository import GLib
 
 from gajim.common import app
 from gajim.common.events import DBMigrationError
@@ -66,9 +67,9 @@ def _on_progress(self, event: DBMigrationProgress) -> None:
         self._ui.stack.set_visible_child_name('progress-page')
         self._ui.status_label.set_text(f'{event.value} %')
 
-        # TODO GTK4
-        while Gtk.events_pending():
-            Gtk.main_iteration()
+        context = GLib.MainContext.default()
+        while context.pending():
+            context.iteration(may_block=False)
 
     def _on_finished(self, event: DBMigrationFinished) -> None:
         self._ui.stack.set_visible_child_name('success-page')