fix generation of locale: fr.po is latin-1 and was specified as utf-8

This *should* fix issue2550546 -- at least I can now say "make" in the
locale directory without errors.

Author: Ralf Schlatterbeck

locale/fr.po

@@ -16,7 +16,7 @@ msgstr ""
 "Last-Translator: Stéphane Raimbault <[email protected]>\n"
 "Language-Team: GNOME French Team <[email protected]>\n"
 "MIME-Version: 1.0\n"
-"Content-Type: text/plain; charset=utf-8\n"
+"Content-Type: text/plain; charset=ISO-8859-1\n"
 "Content-Transfer-Encoding: 8bit\n"
 "Plural-Forms: nplurals=2; plural=n>1;\n"