Update privdrop requirement from 0.3.4 to 0.5.0

Updates the requirements on [privdrop](https://github.com/jedisct1/rust-privdrop) to permit the latest version.
- [Release notes](https://github.com/jedisct1/rust-privdrop/releases)
- [Commits](https://github.com/jedisct1/rust-privdrop/commits/0.5.0)

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

Cargo.toml

@@ -29,7 +29,7 @@ libsodium-sys-stable= "1.19.10"
 log = { version = "0.4.11", features = ["std", "release_max_level_debug"] }
 socket2 = "0.3"
 parking_lot = "0.11"
-privdrop = "0.3.4"
+privdrop = "0.5.0"
 rand = "0.7"
 rustc-hash = "1"
 serde = "1.0"