fix clippy warning

integration-tests/tests/common/mod.rs

@@ -41,8 +41,8 @@ impl Drop for Process {
 }
 
 pub async fn spawn_node() -> (Api, Client, Process) {
-    let duniter_binary_path =
-        std::env::var("DUNITER_BINARY_PATH").unwrap_or("../target/debug/duniter".to_owned());
+    let duniter_binary_path = std::env::var("DUNITER_BINARY_PATH")
+        .unwrap_or_else(|_| "../target/debug/duniter".to_owned());
 
     let p2p_port = portpicker::pick_unused_port().expect("No ports free");
     let rpc_port = portpicker::pick_unused_port().expect("No ports free");