fix(c-bridge): properly read testnet environment config from envars

Author: guidiaz

bridges/centralized-ethereum/src/main.rs

@@ -1,6 +1,7 @@
 //! Witnet <> Ethereum bridge
 
 use actix::{Actor, System, SystemRegistry};
+use witnet_data_structures::chain::Environment;
 use std::{path::PathBuf, process::exit, sync::Arc};
 use structopt::StructOpt;
 
@@ -59,9 +60,15 @@ fn main() {
 fn run(callback: fn()) -> Result<(), String> {
     let app = App::from_args();
     let config = if app.env {
-        config::from_env()
+        let config = config::from_env()
             .map(Arc::new)
-            .map_err(|e| format!("Error reading configuration from environment: {}", e))?
+            .map_err(|e| format!("Error reading configuration from environment: {}", e))?;
+        witnet_data_structures::set_environment(if config.witnet_testnet {
+            Environment::Testnet
+        } else {
+            Environment::Mainnet
+        });
+        config
     } else {
         config::from_file(
             app.config