Fix issue template URL to point to new template chooser

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

README.md

@@ -23,7 +23,7 @@ And in the works for the [coming versions](https://github.com/nextcloud/mail/mil
 * :books: Proper grouping of message threads
 * :package: Folder management
 
-If you experience any issues or have any suggestions for improvement, use the [issue tracker](https://github.com/nextcloud/mail/issues). Please follow the [issue template](https://raw.githubusercontent.com/nextcloud/mail/master/.github/issue_template.md) so we get the info needed to debug and fix the problem. Thanks!
+If you experience any issues or have any suggestions for improvement, use the [issue tracker](https://github.com/nextcloud/mail/issues). Please follow the [issue template chooser](https://github.com/nextcloud/mail/issues/new/choose) so we get the info needed to debug and fix the problem. Thanks!
 
 ## Development setup