Issue #17557: Fix os.getgroups() to work with the modified behavior of
getgroups(2) on OS X 10.8.  Original patch by Mateusz Lenik.
diff --git a/Misc/ACKS b/Misc/ACKS
index aaa8dd4..54fa661f 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -721,6 +721,7 @@
 Luke Kenneth Casson Leighton
 Tshepang Lekhonkhobe
 Marc-André Lemburg
+Mateusz Lenik
 John Lenton
 Kostyantyn Leschenko
 Christopher Tur Lesniewski-Laas