bpo-37441: Fix wrong PyErr_SetImportErrorSubclass signature in doc (GH-14453)

Doc/c-api/exceptions.rst

@@ -320,7 +320,7 @@ an error value).
    :mod:`warnings` module and the :option:`-W` option in the command line
    documentation.  There is no C API for warning control.
 
-.. c:function:: PyObject* PyErr_SetImportErrorSubclass(PyObject *msg, PyObject *name, PyObject *path)
+.. c:function:: PyObject* PyErr_SetImportErrorSubclass(PyObject *exception, PyObject *msg, PyObject *name, PyObject *path)
 
    Much like :c:func:`PyErr_SetImportError` but this function allows for
    specifying a subclass of :exc:`ImportError` to raise.