downgrade no-std-net for now

At least till dunmatt/no-std-net#16 is shipped.

Author: rushmorem

Cargo.toml

@@ -23,7 +23,7 @@ optional = true
 
 # requires Rust v1.46
 [dependencies.no-std-net]
-version = "0.6.0"
+version = "0.5.0"
 default-features = false
 features = ["serde"]
 optional = true