drop duplicated section from CHANGELOG

This 2.1.2 section from the changelog was duplicated.

78a02555e5 was coming from extra 2.1.2 information but the section
was already here since 94a0d2afb4.

CHANGELOG.md

@@ -398,20 +398,6 @@ Module fixes:
 
 ###Incompatible Changes:
 
-* Use of `_fixup_perms` with `recursive=True` (the default) is no longer supported.
-  Custom action plugins using `_fixup_perms` will require changes unless they already use `recursive=False`.
-  Use `_fixup_perms2` if support for previous releases is not required.
-  Otherwise use `_fixup_perms` with `recursive=False`.
-
-## 2.1.2 "The Song Remains the Same"
-
-###Deprecations:
-
-* Deprecated the use of `_fixup_perms`. Use `_fixup_perms2` instead.
-  This change only impacts custom action plugins using `_fixup_perms`.
-
-###Incompatible Changes:
-
 * Use of `_fixup_perms` with `recursive=True` (the default) is no longer supported.
   Custom action plugins using `_fixup_perms` will require changes unless they already use `recursive=False`.
   Use `_fixup_perms2` if support for previous releases is not required.