Changelog 1.15.6

Unforunately go-gitea#17435 is a somewhat critical bug and therefore we should
really release 1.15.6 as soon as possible.

 ## [1.15.6](https://github.com/go-gitea/gitea/releases/tag/v1.15.6) - 2021-10-27

* BUGFIXES
  * Prevent panic in serv.go with Deploy Keys (go-gitea#17434) (go-gitea#17435)
  * Fix CSV render error (go-gitea#17406) (go-gitea#17431)
  * Read expected buffer size (go-gitea#17409) (go-gitea#17430)

Signed-off-by: Andrew Thornton <art27@cantab.net>

CHANGELOG.md

@@ -4,6 +4,13 @@ This changelog goes through all the changes that have been made in each release
 without substantial changes to our git log; to see the highlights of what has
 been added to each release, please refer to the [blog](https://blog.gitea.io).
 
+## [1.15.6](https://github.com/go-gitea/gitea/releases/tag/v1.15.6) - 2021-10-27
+
+* BUGFIXES
+  * Prevent panic in serv.go with Deploy Keys (#17434) (#17435)
+  * Fix CSV render error (#17406) (#17431)
+  * Read expected buffer size (#17409) (#17430)
+
 ## [1.15.5](https://github.com/go-gitea/gitea/releases/tag/v1.15.5) - 2021-10-21
 
 * SECURITY