Use half-close when closing the socking in HttpServerEarlyClientCloseTest.

tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart

Index: tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart
diff --git a/tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart b/tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart
index bf0cf0e0ccf03ea7d60734b543a3f573e2d6499e..9df075c510c7ce5fc5e74b1392d30cc9ced39b7a 100644
--- a/tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart
+++ b/tests/standalone/src/io/HttpServerEarlyClientCloseTest.dart
@@ -8,7 +8,7 @@ void sendData(List<int> data, int port) {
       Expect.fail("No data response was expected");
     };
     socket.outputStream.onNoPendingWrites = () {
-      socket.close(false);
+      socket.close(true);
     };
     socket.outputStream.write(data);
   };