chore(deps): bump github.com/mrz1836/postmark from 1.6.3 to 1.6.4

Bumps [github.com/mrz1836/postmark](https://github.com/mrz1836/postmark) from 1.6.3 to 1.6.4.
- [Release notes](https://github.com/mrz1836/postmark/releases)
- [Changelog](https://github.com/mrz1836/postmark/blob/master/.goreleaser.yml)
- [Commits](mrz1836/postmark@v1.6.3...v1.6.4)

---
updated-dependencies:
- dependency-name: github.com/mrz1836/postmark
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/jinzhu/gorm v1.9.16
 	github.com/joho/godotenv v1.5.1
 	github.com/mediocregopher/radix/v4 v4.1.4
-	github.com/mrz1836/postmark v1.6.3
+	github.com/mrz1836/postmark v1.6.4
 	github.com/pilinux/argon2 v0.9.0
 	github.com/pilinux/crypt v0.0.3
 	github.com/pilinux/libgo v0.0.5

go.sum

@@ -103,8 +103,8 @@ github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjY
 github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe/go.mod h1:wL8QJuTMNUDYhXwkmfOly8iTdp5TEcJFWZD2D7SIkUc=
 github.com/montanaflynn/stats v0.7.1 h1:etflOAAHORrCC44V+aR6Ftzort912ZU+YLiSTuV8eaE=
 github.com/montanaflynn/stats v0.7.1/go.mod h1:etXPPgVO6n31NxCd9KQUMvCM+ve0ruNzt6R8Bnaayow=
-github.com/mrz1836/postmark v1.6.3 h1:g5Zv6hGZfqTR79Xb7my5O1aVuiBxWQ0jI2jFzu+Ou9k=
-github.com/mrz1836/postmark v1.6.3/go.mod h1:6z5MxAH00Kj44owtQaryv9Pbqp5OKT3wWcRSydB0p0A=
+github.com/mrz1836/postmark v1.6.4 h1:x5g0zjFE1q1wOgZ3N22rtGMyfKd3GBo4O874cAUw6bQ=
+github.com/mrz1836/postmark v1.6.4/go.mod h1:6z5MxAH00Kj44owtQaryv9Pbqp5OKT3wWcRSydB0p0A=
 github.com/pelletier/go-toml/v2 v2.0.9 h1:uH2qQXheeefCCkuBBSLi7jCiSmj3VRh2+Goq2N7Xxu0=
 github.com/pelletier/go-toml/v2 v2.0.9/go.mod h1:tJU2Z3ZkXwnxa4DPO899bsyIoywizdUvyaeZurnPPDc=
 github.com/pilinux/argon2 v0.9.0 h1:vVr74dscMFP3P19vwSQUuMfBf8WWGuv5F/yJYY6E07E=