backport jhylton's checkin of

    revision 2.2 of cellobject.h

Cells are not VAR objects.

Noted by Jason Orendorff, SF #520768.

Bug fix candidate for 2.1 & 2.2.

Include/cellobject.h

@@ -7,7 +7,7 @@ extern "C" {
 #endif
 
 typedef struct {
-	PyObject_VAR_HEAD
+	PyObject_HEAD
 	PyObject *ob_ref;
 } PyCellObject;