Add What's New entry for the no-absolute-import check

PCManticore · PCManticore · commit 9125084de6d3 · 2017-11-11T13:16:14.000+01:00
diff --git a/doc/whatsnew/1.8.rst b/doc/whatsnew/1.8.rst
@@ -323,3 +323,5 @@ 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.
