Update changelog - release note for #667

CHANGELOG.txt

@@ -18,6 +18,7 @@ Changelog
  * Fix: The external image URL generator no longer stores generated images in Django's cache
  * Fix: Elasticsearch backend can now search querysets that have been filtered with an 'in' clause of a non-list type (such as a ValuesListQuerySet)
  * Fix: It is now easier to move pages to the beginning and end of their section
+ * Fix: Image rendering no longer creates erroneous duplicate Rendition records when the focal point is blank.
 
 0.6 (11.09.2014)
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