poisson distribution of cows

[demo] / external / libimago

diff --git a/external/libimago b/external/libimago
index 843ac48..2228b92 160000 (submodule)
--- a/external/libimago
+++ b/external/libimago
@@ -1 +1 @@
-Subproject commit 843ac48c7cd58166bb9dc0d49097c1b0ae7e2029
+Subproject commit 2228b925b87ee5458bd59611c11fc98c051446cc