Clean up unused code

Tests/XXMessengerClientTests/Messenger/Functions/MessengerSendFileTests.swift

@@ -5,8 +5,6 @@ import XXClient
 
 final class MessengerSendFileTests: XCTestCase {
   func testSendFile() throws {
-    let e2eFileTransferParams = "e2eFileTransferParams".data(using: .utf8)!
-    let fileTransferParams = "fileTransferParams".data(using: .utf8)!
     let newTransferId = "transferId".data(using: .utf8)!
 
     var didSendFile: [FileTransferSend.Params] = []

Tests/XXMessengerClientTests/Messenger/Functions/MessengerStartFileTransferTests.swift

@@ -28,8 +28,7 @@ final class MessengerStartFileTransferTests: XCTestCase {
     env.initFileTransfer.run = { params, callback in
       didInitFileTransfer.append(params)
       receiveFileCallback = callback
-      var fileTransfer: FileTransfer = .unimplemented
-      return fileTransfer
+      return .unimplemented
     }
     env.fileTransfer.set = {
       didSetFileTransfer.append($0)