mod_smacks: Skip hibernation logic if session was closed or replaced The resumption_token is removed when the session is closed via the pre-session-close event, signaling that it cannot be resumed, and therefore no hibernation timeout logic should be invoked. Fixes that if a session somehow is replaced by a new one using the same resource (which is the common behavior), the old session would still be around until it times out at which point it sends `<presence type="unavailable"/>` which would look as if it came from the new session, ie appearing offline to everyone including MUCs.

--- a/plugins/mod_smacks.lua	Thu Dec 16 22:42:08 2021 +0100
+++ b/plugins/mod_smacks.lua	Thu Dec 16 22:59:51 2021 +0100
@@ -436,6 +436,10 @@
 		if session.destroyed then
 			session.log("debug", "The session has already been destroyed");
 			return
+		elseif not session.resumption_token then
+			-- This should normally not happen, the watchdog should be canceled from session:close()
+			session.log("debug", "The session has already been resumed or replaced");
+			return
 		end
 
 		session.log("debug", "Destroying session for hibernating too long");