message: storage: refine Cargo.toml
  Simpilify refine Cargo.toml for readability.
diff: @@ -4,32 +4,30 @@ version = "0.5.0"
  authors = ["The Nydus Developers"]
  edition = "2018"
  -# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
  -
  [dependencies]
  anyhow = "1.0.35"
  arc-swap = "0.4.6"
  -libc = "0.2"
  -nix = "0.17.0"
  -vm-memory = "0.6"
  +base64 = { version = ">=0.12.0", optional = true }
  +bitflags = ">=1.1.0"
  +flate2 = { version = "1.0", features = ["miniz-sys"], default-features = false }
  +futures = "0.3"
  governor = "0.3.1"
  +hmac = { version = "0.8.1", optional = true }
  +httpdate = { version = "1.0", optional = true }
  +libc = "0.2"
  log = "0.4.8"
  +lz4-sys = "1.9.2"
  +nix = "0.17.0"
  +reqwest = { version = "0.11.0", features = ["blocking", "json"], optional = true }
  serde = { version = ">=1.0.27", features = ["serde_derive", "rc"] }
  serde_json = ">=1.0.9"
  serde_with = { version = "1.6.0", features = ["macros"] }
  -futures = "0.3"
  -flate2 = { version = "1.0", features = ["miniz-sys"], default-features = false }
  -lz4-sys = "1.9.2"
  -bitflags = ">=1.1.0"
  -spmc = "0.3.0"
  -base64 = { version = ">=0.12.0", optional = true }
  sha2 = { version = "0.9.1", optional = true }
  sha-1 = { version = "0.9.1", optional = true }
  -hmac = { version = "0.8.1", optional = true }
  -url = { version = "2.1.1", optional = true }
  -httpdate = { version = "1.0", optional = true }
  -reqwest = { version = "0.11.0", features = ["blocking", "json"], optional = true }
  +spmc = "0.3.0"
  tokio = { version = "1.5.0", features = ["rt-multi-thread"] }
  +url = { version = "2.1.1", optional = true }
  +vm-memory = "0.6"
  fuse-backend-rs = { git = "https://github.com/cloud-hypervisor/fuse-backend-rs.git", rev = "5a4b2ac"}
  