Annotate the type for Page.__gsignals__ to fix the mypy failure

gajim/gtk/account_wizard.py

@@ -12,7 +12,6 @@
 # You should have received a copy of the GNU General Public License
 # along with Gajim. If not, see <http://www.gnu.org/licenses/>.
 
-# type: ignore
 import logging
 
 from gi.repository import Gdk

gajim/gtk/assistant.py

@@ -180,7 +180,7 @@ def __on_destroy(self, *args):
 
 class Page(Gtk.Box):
 
-    __gsignals__ = {
+    __gsignals__: dict = {
         'update-page-complete': (GObject.SignalFlags.RUN_LAST, None, ()),
     }