Drop a sentence of arguable value

Author: hartwork

Doc/library/pyexpat.rst

@@ -622,7 +622,6 @@ otherwise stated.
       if :class:`xmlparser` is used with user-provided XML content.
       Please reflect on your `threat model <https://en.wikipedia.org/wiki/Threat_model>`_
       before implementing this handler.
-      By default, :class:`xmlparser` is safe from these threats.
 
    Called for references to external entities.  *base* is the current base, as set
    by a previous call to :meth:`SetBase`.  The public and system identifiers,