Tests: Guard text writes

StackExchange.Redis.Tests/Helpers/TextWriterOutputHelper.cs

@@ -14,9 +14,18 @@ public class TextWriterOutputHelper : TextWriter
 
         public override void WriteLine(string value)
         {
-            base.Write(DateTime.UtcNow.ToString("HH:mm:ss.fff"));
-            base.Write(": ");
-            base.WriteLine(value);
+            try
+            {
+                base.Write(DateTime.UtcNow.ToString("HH:mm:ss.fff"));
+                base.Write(": ");
+                base.WriteLine(value);
+            }
+            catch (Exception ex)
+            {
+                Console.Write("Attempted to write: ");
+                Console.WriteLine(value);
+                Console.WriteLine(ex);
+            }
         }
 
         public override void Write(char value)