http.client: Add pristine from CPython 3.3.3.

http.client/http/client.py

@@ -273,8 +273,7 @@ def parse_headers(fp, _class=HTTPMessage):
 
 _strict_sentinel = object()
 
-class HTTPResponse:
-#class HTTPResponse(io.RawIOBase):
+class HTTPResponse(io.RawIOBase):
 
     # See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details.
 
@@ -1038,7 +1037,7 @@ class HTTPConnection:
             header = header.encode('ascii')
         values = list(values)
         for i, one_value in enumerate(values):
-            if isinstance(one_value, str):
+            if hasattr(one_value, 'encode'):
                 values[i] = one_value.encode('latin-1')
             elif isinstance(one_value, int):
                 values[i] = str(one_value).encode('ascii')