typo in CHANGES.txt

doc/CHANGES.txt

@@ -10,8 +10,8 @@ Zope Changes
 
       - Collector #2235: A number of ZCatalog methods were doing boolean
         evaluation of objects that implemented __len__ instead of checking
-        them against None. Replace a number of "if not obj" with
-        "if obj is not None".
+        them against None. Replaced a number of "if not obj" with
+        "if obj is None".
 
       - Fix yet another resTructuredText glitch, and add tests (test
         backported from 2.9, which was not in fact vulnerable).