Fix spelling in changelog

CHANGELOG

@@ -10,7 +10,7 @@ v 7.8.0
   - Add diff syntax highlighting in email-on-push service notifications (Hannes Rosenögger)
   - Add API endpoint to fetch all changes on a MergeRequest (Jeroen van Baarsen)
   - View note image attachments in new tab when clicked instead of downloading them
-  - Improve sorting logic in UI and API. Explicitly define what sorting method used by default
+  - Improve sorting logic in UI and API. Explicitly define what sorting method is used by default
   - Allow more variations for commit messages closing issues (Julien Bianchi and Hannes Rosenögger)
   - 
   - 
@@ -1126,4 +1126,4 @@ v 0.8.0
   - stability
   - security fixes
   - increased test coverage
-  - email notification
+  - email notification
\ No newline at end of file