Update Rust crate futures-channel to 0.3.18

Author: renovate-bot

Cargo.lock

@@ -54,7 +54,7 @@ diesel_full_text_search = "1.0.1"
 diesel_migrations = { version = "1.4.0", features = ["postgres"] }
 dotenv = "0.15"
 flate2 = "1.0"
-futures-channel = { version = "0.3.17", default-features = false }
+futures-channel = { version = "0.3.18", default-features = false }
 futures-util = "0.3"
 git2 = "0.13.24"
 hex = "0.4"