Update CHANGELOG.md

Fix style in CHANGELOG.md

Closes #4127.

Author: chinnichaitanya

CHANGELOG.md

@@ -47,7 +47,7 @@ styles
 
 #### Bug Fixes
 
-* ** sidenav:** corrected use of internal $toggleOpen() ([6f72befb](https://github.com/angular/material/commit/6f72befb))
+* **sidenav:** corrected use of internal $toggleOpen() ([6f72befb](https://github.com/angular/material/commit/6f72befb))
 * **$mdConstant:** fix overlapping in media-queries ([61a0e539](https://github.com/angular/material/commit/61a0e539), closes [#3423](https://github.com/angular/material/issues/3423), [#3451](https://github.com/angular/material/issues/3451))
 * **autocomplete:**
   * hitting escape once again clears the search text ([99e8e2c2](https://github.com/angular/material/commit/99e8e2c2), closes [#3847](https://github.com/angular/material/issues/3847))