Removed biblio_year_text from spaces_overrides  #2089

That functionality is no longer supported.  Since we now offer 5 text years instead of 2, there's less reason to let people override submitted.
Added type var to update hook to make rbran feel better.  #2089
Merge pull request #2091 from openscholar/2089-biblio_years

Removed biblio_year_text from spaces_overrides  #2089