Correct error message in io.open():
closefd=True is the only accepted value with a file name.
diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index d7f7893..b33b745 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -249,7 +249,7 @@
 		self->closefd = 1;
 		if (!closefd) {
 			PyErr_SetString(PyExc_ValueError,
-                            "Cannot use closefd=True with file name");
+                            "Cannot use closefd=False with file name");
 			goto error;
 		}