"Use only numbers at %field." message should always include field name

I was trying to use a numeric rule to validate a form field, but kept getting the following unhelpful message in the browser with invalid entries:

Use only numbers at %field.

It seems that only some types of validation substitute %field with the name of the field, so the attached patch changes behaviour so %field is always substituted with the name of the field, which corrects the above message to;

Use only numbers at Survey ID.