Make "lintchanges.py" pass on maint-0.2.7

changes/bug17906

@@ -1,4 +1,4 @@
   o Minor features (authorities):
-    - Update the V3 identity key for dannenberg, it was changed on
+    - Update the V3 identity key for dannenberg: it was changed on
       18 November 2015.
-      Closes task #17906. Patch by "teor".
+      Closes task 17906. Patch by "teor".