f - Update BackgroundProcessor's docs on timer_tick_occurred

lightning-background-processor/src/lib.rs

@@ -35,7 +35,7 @@ use std::ops::Deref;
 ///   writing it to disk/backups by invoking the callback given to it at startup.
 ///   [`ChannelManager`] persistence should be done in the background.
 /// * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
-///   every minute.
+///   at the appropriate intervals.
 ///
 /// # Note
 ///