Fix CHANGELOG markup

Before:
![2014-12-30 1 12 51](https://cloud.githubusercontent.com/assets/290782/5570187/08a834a2-8fc1-11e4-9e5d-67318a35d549.png)

After:
![2014-12-30 1 12 44](https://cloud.githubusercontent.com/assets/290782/5570188/08aadc48-8fc1-11e4-8bf7-84b6f6c2b4b3.png)