+ mention mpmath issue 473

Author: skirpichev

peps/pep-0812.rst

@@ -96,10 +96,10 @@ and reccuring issues in the CPython bugtracker (here is an incomplete list:
 :cpython-issue:`84450`, :cpython-issue:`85657`, :cpython-issue:`105027`,
 :cpython-issue:`107854`, :cpython-issue:`112176`, :cpython-issue:`122615`) and
 mathematical libraries in the Python ecosystem (e.g. `numpy/numpy#26310
-<https://github.com/numpy/numpy/issues/26310>`_ or `mpmath/mpmath#774
-<https://github.com/mpmath/mpmath/issues/774#issuecomment-2034375377>`_).
-Among others, broken ``repr(eval(repr(x))) == repr(x)`` invariant for complex
-numbers:
+<https://github.com/numpy/numpy/issues/26310>`_, `mpmath/mpmath#473
+<https://github.com/mpmath/mpmath/issues/473>`_, `mpmath/mpmath#774
+<https://github.com/mpmath/mpmath/issues/774>`_).  Among others, broken
+``repr(eval(repr(x))) == repr(x)`` invariant for complex numbers:
 
 .. code:: pycon