remove unused import

Change-Id: I2337a3ba638f4718bfc71abedf3fae5ae0ebb189
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/431641
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Auto-Submit: Jake Macdonald <jakemac@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>

samples/ffi/httpIG/lib/http.dart

@@ -7,7 +7,6 @@ import 'dart:convert';
 import 'dart:ffi';
 import 'dart:isolate';
 import 'dart:io';
-import 'dart:typed_data';
 
 import 'package:ffi/ffi.dart';