Fix formatting in change log. (#14383)
The two following headings are not correctly formatted in the change log:
= 2022.3.2 =
== Security Fixes ==
They appear with the t2t formatting character = instead.
This is due to a list which is not terminated with an empty item as required in t2t syntax.
Description of user facing changes
Headings are correctly formatted.
Description of development approach
Add empty list item to close the list and thus fix t2t formatting.
