fix linter

Author: KirillKurdyukov

src/Ydb.Sdk/tests/Topic/WriterMockTests.cs

@@ -654,7 +654,7 @@ public async Task WriteAsync_WhenCancelTaskInOnOfTwoMessagesInFlightBuffer_Retur
         Assert.Equal("Transport error in the WriterSession on write messages",
             writerExceptionAfterResetSession.Message);
         Assert.Equal(StatusCode.Cancelled, writerExceptionAfterResetSession.Status.StatusCode);
-        
+
         ctx.Cancel(); // reconnect write invoke cancel on cancellation token
         moveSecondNextSource.SetResult(true);
         await nextCompleted.Task;