Streaming integration tests: remove unexpected error assumption

For some reason instead of fixing unexpected errors, we made tests
assert they indeed trigger... Now that the errors are fixed these were
failing

test/integration/mastodon_websocket_test.exs

@@ -99,30 +99,30 @@ test "accepts valid tokens", state do
     test "accepts the 'user' stream", %{token: token} = _state do
       assert {:ok, _} = start_socket("?stream=user&access_token=#{token.token}")
 
-      assert capture_log(fn ->
+      capture_log(fn ->
         assert {:error, {401, _}} = start_socket("?stream=user")
         Process.sleep(30)
-             end) =~ ":badarg"
+      end)
     end
 
     test "accepts the 'user:notification' stream", %{token: token} = _state do
       assert {:ok, _} = start_socket("?stream=user:notification&access_token=#{token.token}")
 
-      assert capture_log(fn ->
+      capture_log(fn ->
         assert {:error, {401, _}} = start_socket("?stream=user:notification")
         Process.sleep(30)
-             end) =~ ":badarg"
+      end)
     end
 
     test "accepts valid token on Sec-WebSocket-Protocol header", %{token: token} do
       assert {:ok, _} = start_socket("?stream=user", [{"Sec-WebSocket-Protocol", token.token}])
 
-      assert capture_log(fn ->
+      capture_log(fn ->
         assert {:error, {401, _}} =
                  start_socket("?stream=user", [{"Sec-WebSocket-Protocol", "I am a friend"}])
 
         Process.sleep(30)
-             end) =~ ":badarg"
+      end)
     end
   end
 end