use a default LANG var only under windows

src/common/i18n.py

@@ -37,16 +37,17 @@ else:
 # according to the environment variables
 locale.setlocale(locale.LC_ALL, '')
 
-## Set, if needed, a value in LANG environmental variable ##
-# get LANG, fallback to ''
-lang = os.environ.get('LANG')
-if not lang:
-	default_lang = locale.getdefaultlocale()[0] # en_US, fr_FR, el_GR etc..
-	if default_lang:
-		lang = default_lang
+## For win: set, if needed, a value in LANG environmental variable ##
+if os.name == 'nt':
+	# get LANG, fallback to ''
+	lang = os.environ.get('LANG')
+	if not lang:
+		default_lang = locale.getdefaultlocale()[0] # en_US, fr_FR, el_GR etc..
+		if default_lang:
+			lang = default_lang
 
-if lang:
-	os.environ['LANG'] = lang
+	if lang:
+		os.environ['LANG'] = lang
 
 _translation = None