Bump tokio-util from 0.7.3 to 0.7.4

Bumps [tokio-util](https://github.com/tokio-rs/tokio) from 0.7.3 to 0.7.4.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/compare/tokio-util-0.7.3...tokio-util-0.7.4)

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

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

Cargo.lock

@@ -5108,9 +5108,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.20.1"
+version = "1.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a8325f63a7d4774dd041e363b2409ed1c5cbbd0f867795e661df066b2b0a581"
+checksum = "0020c875007ad96677dcc890298f4b942882c5d4eb7cc8f439fc3bf813dc9c95"
 dependencies = [
  "autocfg 1.1.0",
  "bytes",
@@ -5167,9 +5167,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-util"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc463cd8deddc3770d20f9852143d50bf6094e640b485cb2e189a2099085ff45"
+checksum = "0bb2e075f03b3d66d8d8785356224ba688d2906a371015e225beeb65ca92c740"
 dependencies = [
  "bytes",
  "futures-core",