Fixes the select widget overflow out of the modal in FF.
Fixes the select widget overflow out of the modal in FF.

plone/mockup,domruf/mockup,domruf/mockup,plone/mockup,derFreitag/mockup,plone/mockup,derFreitag/mockup,derFreitag/mockup,domruf/mockup,domruf/mockup,derFreitag/mockup