Free clients with session expiry > 0 on exit.

src/mosquitto.c

@@ -391,6 +391,7 @@ int main(int argc, char *argv[])
 		context__send_will(&int_db, ctxt);
 	}
 	will_delay__send_all(&int_db);
+	session_expiry__remove_all(&int_db);
 
 #ifdef WITH_PERSISTENCE
 	if(config.persistence){

src/mosquitto_broker_internal.h

@@ -653,6 +653,7 @@ int mosquitto_psk_key_get_default(struct mosquitto_db *db, struct mosquitto *con
  * ============================================================ */
 int session_expiry__add(struct mosquitto *context);
 void session_expiry__remove(struct mosquitto *context);
+void session_expiry__remove_all(struct mosquitto_db *db);
 void session_expiry__check(struct mosquitto_db *db, time_t now);
 void session_expiry__send_all(struct mosquitto_db *db);