fix title decoding error. unknown-8bit charset

tests/test_imap.py

@@ -0,0 +1,17 @@
+#!/usr/bin/python
+# -*- coding: UTF-8 -*-
+
+import os
+import unittest
+
+from stacosys.core.imap import _to_utf8, _email_non_ascii_to_uft8
+from email.header import Header
+
+
+class ImapTestCase(unittest.TestCase):
+
+    def test_utf8_decode(self):
+        h = Header(s="Chez Darty vous avez re\udcc3\udca7u un nouvel aspirateur Vacuum gratuit jl8nz",
+                   charset="unknown-8bit")
+        decoded = _email_non_ascii_to_uft8(h)
+        self.assertEquals(decoded, "Chez Darty vous avez reçu un nouvel aspirateur Vacuum gratuit jl8nz")