Properly destroy unclosed channels at meshlink_close() time.

[meshlink] / src / utcp

diff --git a/src/utcp b/src/utcp
index 0f36bb393e49ecab387b1bfe88741a337d4a8834..1d8aa0d5a55bb871ce56bca355ade80b08a7c1e5 160000 (submodule)
--- a/src/utcp
+++ b/src/utcp
@@ -1 +1 @@
-Subproject commit 0f36bb393e49ecab387b1bfe88741a337d4a8834
+Subproject commit 1d8aa0d5a55bb871ce56bca355ade80b08a7c1e5