tpl: Fix baseof.html in error message
tpl: Fix baseof.html in error message

This fix should also make the template loadin slightly faster, as we avoid to reparse the baseof.html files more than one time.

Fixes #5288

anthonyfok/hugo,mdhender/hugo,gohugoio/hugo,fedelibre/hugo,fedelibre/hugo,fedelibre/hugo,mdhender/hugo,anthonyfok/hugo,gohugoio/hugo,gohugoio/hugo,mdhender/hugo,anthonyfok/hugo,mdhender/hugo,fedelibre/hugo