restore the 1.9.2 changes target so docs will build

Cris Ewing

2018-05-15 0820271a6701853aec036153a86913a9d58e63ed

 CHANGES.txt

@@ -8,6 +8,8 @@
  error code.
  See https://github.com/Pylons/pyramid/pull/3280

.. _changes_1.9.2:

1.9.2 (2018-04-23)
==================