cargo: bump log from 0.4.14 to 0.4.16

Bumps [log](https://github.com/rust-lang/log) from 0.4.14 to 0.4.16.
- [Release notes](https://github.com/rust-lang/log/releases)
- [Changelog](https://github.com/rust-lang/log/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/log/commits)

---
updated-dependencies:
- dependency-name: log
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.toml

@@ -38,7 +38,7 @@ image = { version = "0.24.1", default-features=false, features = ["gif", "jpeg",
 kamadak-exif = "0.5"
 lettre_email = { git = "https://github.com/deltachat/lettre", branch = "master" }
 libc = "0.2"
-log = {version = "0.4.8", optional = true }
+log = {version = "0.4.16", optional = true }
 mailparse = "0.13"
 native-tls = "0.2"
 num_cpus = "1.13"