locales: fix installation of some collation files

When the unicode locales files where split off the non unicode locales
be_BY.ISO8859-5 and ca_IT.ISO8859-15 where non installed one due to
a typo, the other one was just missing its entry in the Makefile.

It was only notice a year later, by some postgres developpers as it was
breaking some of their tests.

Reported by: tmunro