Add ChangeLog entry for the new py3k change

doc/whatsnew/1.8.rst

@@ -347,4 +347,6 @@ Other Changes
 * Fix of false positive ``useless-else-on-loop`` message when break statements
   are deeply nested inside loop.
-* The Python 3 porting checker no longer emits multiple `no-absolute-import` per file.
\ No newline at end of file
+* The Python 3 porting checker no longer emits multiple `no-absolute-import` per file.
+
+* The Python 3 porting checker respects disabled checkers found in the config file.