python: Use six.unichr().

six.unichr() is equivalent to unichr() in Python 2
and chr() in Python 3.

Signed-off-by: Russell Bryant <russell@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>

python/ovs/json.py

@@ -408,7 +408,7 @@ def __lex_finish_string(self):
                 inp = inp[6:]
             else:
                 code_point = c0
-            out += unichr(code_point)
+            out += six.unichr(code_point)
         self.__parser_input('string', out)
 
     def __lex_string_escape(self, c):