String in test for #822 was meant to be a bytestring, fixes it.

IPython/core/tests/test_interactiveshell.py

@@ -201,7 +201,7 b' class InteractiveShellTestCase(unittest.TestCase):'
 
     def test_var_expand(self):
         ip = get_ipython()
-        ip.user_ns['f'] = u'Ca\xc3\xb1o'
+        ip.user_ns['f'] = 'Ca\xc3\xb1o'
         # This should not raise any exception:
         ip.var_expand(u'echo $f')