Fix February month name in de_AT locale

The current de_AT locale defines "Feber" for the month of February,
which is correct in some parts of Austria, but is not the standards.
This patch fixes the problem by changing it to the standards version
"Februar".

2012-04-29  Aurelien Jarno  <aurelien@aurel32.net>

        * locales/de_AT: Change month name from "Feber" to "Februar".