E debian-changelog-file-uses-obsolete-national-encoding

The Debian changelog file must be valid UTF-8, an encoding of the Unicode character set.

There are many ways to convert a changelog from an obsoleted encoding like ISO-8859-1; you may for example use "iconv" like:

$ iconv -f ISO-8859-1 -t UTF-8 changelog > changelog.new $ mv changelog.new changelog

Refer to Debian Policy Manual section 4.4 (Debian changelog: debian/changelog) for details.