Remove unused import.

client/src/control/response.rs

@@ -112,9 +112,9 @@ mod tests {
   use crate::room::{Membership, Room, Visibility};
 
   use super::{
-    LoginStatusResponse, Response, RoomJoinResponse, RoomLeaveResponse,
-    RoomListResponse, RoomMessageResponse, RoomUserJoinedResponse,
-    RoomUserLeftResponse, UserInfoResponse, UserListResponse,
+    LoginStatusResponse, RoomJoinResponse, RoomLeaveResponse, RoomListResponse,
+    RoomMessageResponse, RoomUserJoinedResponse, RoomUserLeftResponse,
+    UserInfoResponse, UserListResponse,
   };
 
   #[test]