v1.9.2

* BUGFIXES
  * Fix wrong sender when send slack webhook (#7918) (#7924)
  * Upload support text/plain; charset=utf8 (#7899)
  * Lfs/lock: round locked_at timestamp to second (#7872) (#7875)
  * Fix non existent milestone with 500 error (#7867) (#7873)
* SECURITY
  * Fix No PGP signature on 1.9.1 tag (#7874)
  * Release built with go 1.12.9 to fix security fixes in golang std lib, ref: https://groups.google.com/forum/#!msg/golang-announce/oeMaeUnkvVE/a49yvTLqAAAJ
* ENHANCEMENT
  * Fix pull creation with empty changes (#7920) (#7926)
* BUILD
  * Drone/docker: prepare multi-arch release + provide arm64 image (#7571) (#7884)
-----BEGIN PGP SIGNATURE-----
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=m/uq
-----END PGP SIGNATURE-----