Add a changes file for the osx 10.6 compile fix

We forgot to put it into 0.2.2.24-alpha.

changes/osx_forgotten_compilefix

@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - Added a forgotten cast that caused a compile warning on OS X 10.6. Bugfix
+      on 0.2.2.24-alpha.
+