build: bump clap from 2.33.3 to 2.34.0

Bumps [clap](https://github.com/clap-rs/clap) from 2.33.3 to 2.34.0.
- [Release notes](https://github.com/clap-rs/clap/releases)
- [Changelog](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md)
- [Commits](https://github.com/clap-rs/clap/commits)

---
updated-dependencies:
- dependency-name: clap
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

vhost_user_block/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 block_util = { path = "../block_util" }
-clap = { version = "2.33.3", features = ["wrap_help"] }
+clap = { version = "2.34.0", features = ["wrap_help"] }
 env_logger = "0.9.0"
 epoll = "4.3.1"
 libc = "0.2.108"