Fix changelog

Author: ehmicky

CHANGELOG.md

@@ -4,9 +4,9 @@
 
 - Fix
   [`BaseError.normalize(error, NewErrorClass)`](README.md#errorclassnormalizeerror-newerrorclass).
-  `error` is converted to `NewErrorClass` if it was an instance of a
-  `BaseError`'s subclass. However, `error` was not converted when it was an
-  instance of `BaseError` itself, which was incorrect.
+  `error` is not converted to `NewErrorClass` if it is an instance of a
+  `BaseError`'s subclass. However, `error` was converted when it was an instance
+  of `BaseError` itself, which was incorrect.
 
 # 7.1.2