Fixed plural forms formula for the Croatian (hr) localization by manually...

Fixed plural forms formula for the Croatian (hr) localization by manually overriding the header of affected .po files and re-generating .mo files, this seems to be a quirck in Transifex export to PO functionality. Thanks bmihelac fot the report. Refs #15634.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15875 bcc190cf-cafb-0310-a4f2-bffc1f526a37