bpo-39693: mention KeyError in tarfile extractfile documentation (GH-18639)

Co-authored-by: Andrey Darascheka <andrei.daraschenka@leverx.com>
diff --git a/Misc/ACKS b/Misc/ACKS
index 0aab456..404f70e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1957,5 +1957,6 @@
 Doug Zongker
 Peter Åstrand
 Vlad Emelianov
+Andrey Doroschenko
 
 (Entries should be added in rough alphabetical order by last names)