made improvements

backend/src/main/java/com/vaessl/app/connection/ConnectionController.java

@@ -21,7 +21,6 @@ public class ConnectionController {
 
     @PostMapping("/login")
     public ResponseEntity<ConnectionResponse> loginResponse(@Valid @RequestBody ConnectionRequest request) {
-        ConnectionResponse connectionResponse = connectionService.login(request);
-        return ResponseEntity.ok(connectionResponse);
+        return ResponseEntity.ok(connectionService.login(request));
     }
 }