Do not start printing a table when no columns, details:

When all columns are disabled, it was printing:

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Replace it with the message, which is in contrast with errors

Author: YegorStepanov

src/BenchmarkDotNet/Exporters/MarkdownExporter.cs

@@ -139,6 +139,12 @@ private void PrintTable(SummaryTable table, ILogger logger)
                 return;
             }
 
+            if (table.Columns.All(c => !c.NeedToShow))
+            {
+                logger.WriteLine("There are no columns to show ");
+                return;
+            }
+
             table.PrintCommonColumns(logger);
             logger.WriteLine();