Fix error message syntax to allow translation extraction

ihatemoney/forms.py

@@ -160,12 +160,10 @@ class EditProjectForm(FlaskForm):
         ):
             raise ValidationError(
                 _(
-                    (
                     "This project cannot be set to 'no currency'"
                     " because it contains bills in multiple currencies."
                 )
             )
-            )
 
     def update(self, project):
         """Update the project with the information from the form"""