change encoding for windows environment variables from latin_1 to windows-1252

frg-buildfixes/mozilla/TOP-1566826-1-PLASTER-define-ensure_subprocess_env.patch

@@ -38,7 +38,7 @@ diff --git a/python/mozbuild/mozbuild/util.py b/python/mozbuild/mozbuild/util.py
 +    """
 +    def ensure_bytes(value, encoding='utf-8'):
 +        try:
-+            return value.decode('latin_1').encode(encoding)
++            return value.decode('windows-1252').encode(encoding)
 +        except AttributeError:
 +            return value
 +