deckard: update to fix in CI (new dnspython in image)

diff --git a/tests/integration/deckard b/tests/integration/deckard
index 21ac6777893f89363f38a16a041754aae976bac3..594d3b8784f843beb8f1c095f5b9878fc1e84519 160000 (submodule)
--- a/tests/integration/deckard
+++ b/tests/integration/deckard
@@ -1 +1 @@
-Subproject commit 21ac6777893f89363f38a16a041754aae976bac3
+Subproject commit 594d3b8784f843beb8f1c095f5b9878fc1e84519