Update src/Http/Http.Extensions/src/SendFileResponseExtensions.cs

Co-authored-by: Andrew Casey <amcasey@users.noreply.github.com>

Author: paulomorgado

src/Http/Http.Extensions/src/SendFileResponseExtensions.cs

@@ -128,6 +128,7 @@ private static void CheckRange(long offset, long? count, long fileLength)
         ArgumentOutOfRangeException.ThrowIfGreaterThan(offset, fileLength);
         if (count is {} countValue)
         {
+            ArgumentOutOfRangeException.ThrowIfLessThan(countValue, 0, nameof(count));
             ArgumentOutOfRangeException.ThrowIfGreaterThan(countValue, fileLength - offset, nameof(count));
         }
     }