Bump serde from 1.0.125 to 1.0.126 in /src/rust/receiver-mock

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.125 to 1.0.126.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.125...v1.0.126)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/rust/receiver-mock/Cargo.lock

@@ -12,7 +12,7 @@ actix-http = "~2.1.0"
 actix-service = "^1.0"
 actix-rt = "^2"
 bytes = "^0.5.6"
-serde = "1.0.125"
+serde = "1.0.126"
 serde_derive = "1"
 clap = "2.33.1"
 timer = "0.2"