Fix syntax issue in CHANGELOG

Author: fdintino

CHANGELOG.rst

@@ -6,13 +6,13 @@ Changelog
 * Fixed: visual inconsistencies in grappelli tabular inline styles (`#136`_)
 * Fixed: numerous issues with django-polymorphic integration (`#138`_)
 * Feature: Added ``SortableHiddenMixin`` akin to grappelli’s
-`GrappelliSortableHiddenMixin`_ (`#123`_). Thanks `@brandenhall`_!
+  `GrappelliSortableHiddenMixin`_ (`#123`_). Thanks `@brandenhall`_!
 
 .. _#136: https://github.com/theatlantic/django-nested-admin/issues/136
 .. _#138: https://github.com/theatlantic/django-nested-admin/issues/138
 .. _GrappelliSortableHiddenMixin: https://django-grappelli.readthedocs.io/en/2.12.2/customization.html#grappellisortablehiddenmixin
 .. _#123: https://github.com/theatlantic/django-nested-admin/pull/123
-.. @brandenhall_: https://github.com/brandenhall
+.. _@brandenhall: https://github.com/brandenhall
 
 **3.2.2 (Apr 9, 2019)**