Add Robert Lehmann for issue #1766304 patch
diff --git a/Misc/ACKS b/Misc/ACKS
index d419b7e..2e8818a 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -433,6 +433,7 @@
 Vincent Legoll
 Kip Lehman
 Joerg Lehmann
+Robert Lehmann
 Luke Kenneth Casson Leighton
 Marc-Andre Lemburg
 John Lenton