Fixed PR link

CHANGELOG.md

@@ -4,7 +4,7 @@
 - Add error codes to production invariants, with links to the view the full error text. ([@keyanzhang](https://github.com/keyanzhang) in [#6948](https://github.com/facebook/react/pull/6948))
 - Include component stack information in PropType validation warnings. ([@troydemonbreun](https://github.com/troydemonbreun) in [#6398](https://github.com/facebook/react/pull/6398), [@spicyj](https://github.com/spicyj) in [#6771](https://github.com/facebook/react/pull/6771))
 - Include component stack information in key warnings. ([@keyanzhang](https://github.com/keyanzhang) in [#6799](https://github.com/facebook/react/pull/6799))
-- Stop validating props at mount time, only validate at element creation. ([@keyanzhang](https://github.com/keyanzhang) in [#6823](https://github.com/facebook/react/pull/6823))
+- Stop validating props at mount time, only validate at element creation. ([@keyanzhang](https://github.com/keyanzhang) in [#6824](https://github.com/facebook/react/pull/6824))
 - New invariant providing actionable error in missing instance case. ([@yungsters](https://github.com/yungsters) in [#6990](https://github.com/facebook/react/pull/6990))
 - Add `React.PropTypes.symbol` to support ES2015 Symbols as props. ([@puradox](https://github.com/puradox) in [#6377](https://github.com/facebook/react/pull/6377))
 - Fix incorrect coercion of ref or key that are undefined in development ([@gaearon](https://github.com/gaearon) in [#6880](https://github.com/facebook/react/pull/6880))