Fix regression in UsrSctpReliabilityTest

These tests, not run by default, were broken by
https://webrtc-review.googlesource.com/c/src/+/212862.

Bug: webrtc:12339
Change-Id: I442795d72d1a162f5b1abe80f466469b2bc32ed4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/213424
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Taylor <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33738}
diff --git a/media/sctp/usrsctp_transport_reliability_unittest.cc b/media/sctp/usrsctp_transport_reliability_unittest.cc
index f6f34f3..98f04a4 100644
--- a/media/sctp/usrsctp_transport_reliability_unittest.cc
+++ b/media/sctp/usrsctp_transport_reliability_unittest.cc
@@ -250,7 +250,7 @@
   rtc::Event sent_target_messages_count_{true, false};
   std::atomic<uint64_t> num_bytes_sent_ ATOMIC_VAR_INIT(0);
   absl::optional<std::string> last_error_;
-  webrtc::ScopedTaskSafety task_safety_;
+  webrtc::ScopedTaskSafetyDetached task_safety_;
   RTC_DISALLOW_COPY_AND_ASSIGN(SctpDataSender);
 };