Force to compare string with string in selection display

tryton/gui/window/view_form/view/form_gtk/selection.py

@@ -130,7 +130,7 @@ class Selection(WidgetInterface):
         else:
             found = False
             for long_text, sel_value in self._selection.items():
-                if sel_value == value:
+                if str(sel_value) == str(value):
                     child.set_text(long_text)
                     found = True
                     break