Update plomlib (for Jinja autoescaping).

diff --git a/src/plomlib b/src/plomlib
index e7202fcfd78c6a60bd90da789a68c8ec4baf7b1a..dee7c0f6218e6bdd07b477dc5d9e4b5540ffcf4a 160000 (submodule)
--- a/src/plomlib
+++ b/src/plomlib
@@ -1 +1 @@
-Subproject commit e7202fcfd78c6a60bd90da789a68c8ec4baf7b1a
+Subproject commit dee7c0f6218e6bdd07b477dc5d9e4b5540ffcf4a