Fix error message

models/account_fiscalyear.py

@@ -162,7 +162,7 @@
             # Only administrator can reallocate periods.
             if not record.env.uid == SUPERUSER_ID:
                 raise ValidationError(_(
-                    'It not possible to run this action,'
+                    'It is not possible to run this action,'
                     'please contact your administrator.'
                 ))