Remove an now-false statement about there being only one type flag

defined.

Doc/api/api.tex

@@ -2083,9 +2083,7 @@ Returns true is the object \var{o} is a type object.
 
 \begin{cfuncdesc}{int}{PyType_HasFeature}{PyObject *o, int feature}
 Returns true if the type object \var{o} sets the feature
-\var{feature}.  Type features are denoted by single bit flags.  The
-only defined feature flag is \constant{Py_TPFLAGS_HAVE_GETCHARBUFFER}, 
-described in section \ref{buffer-structs}.
+\var{feature}.  Type features are denoted by single bit flags.
 \end{cfuncdesc}