bpo-30395 _PyGILState_Reinit deadlock fix (#1734)

head_lock could be held by another thread when fork happened. We should
reset it to avoid deadlock.
diff --git a/Misc/ACKS b/Misc/ACKS
index 098c801..b72c40c 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -556,6 +556,7 @@
 Daniel Andrade Groppe
 Dag Gruneau
 Filip Gruszczyński
+Andrii Grynenko
 Grzegorz Grzywacz
 Thomas Guettler
 Yuyang Guo