Adjust the language slightly
@@ -3,6 +3,6 @@ Please ensure that your pull request meets the following requirements - thanks !
* Follows our existing [codestyle](https://github.com/k9mail/k-9/wiki/CodeStyle).
* Does not break any unit tests.
* Contains a reference to the issue that it fixes.
-* On cosmetic changes add one or multiple images, if possible.
+* For cosmetic changes add one or multiple images, if possible.
