[docs] Mention correct issue in changelog.

Signed-off-by: Michael Seifert <[email protected]>

Author: seifertm

docs/source/reference/changelog.rst

@@ -4,7 +4,7 @@ Changelog
 
 0.23.3 (UNRELEASED)
 ===================
-- Fixes a bug that caused event loops to be closed prematurely when using async generator fixtures with class scope or wider in a function-scoped test `#708 <https://github.com/pytest-dev/pytest-asyncio/issues/708>`_
+- Fixes a bug that caused event loops to be closed prematurely when using async generator fixtures with class scope or wider in a function-scoped test `#706 <https://github.com/pytest-dev/pytest-asyncio/issues/706>`_
 - Fixes a bug that caused an internal pytest error when using unittest.SkipTest in a module `#711 <https://github.com/pytest-dev/pytest-asyncio/issues/711>`_
 - Fixes a bug that caused an internal pytest error when an ImportWarning is emitted in a module `#713 <https://github.com/pytest-dev/pytest-asyncio/issues/713>`_