The application crashed when we generated hints to attributes with
interpolation arguments in their `human_attribute_name`.
When generating the hint, we used the `custom_label` method to generate
a label and get the `for` attribute and, since we weren't passing a
text, it used the default human attribute name for the field. However,
it crashes if the default attribute name requires an interpolation
argument.
So now, since we were only using the `custom_label` method in order to
get the `for` attribute, we're simply passing an arbitrary text to the
method.
1fa05b1f54