fix: Increase PING_TIMER to 20 seconds

This value was chosen sort of arbitrarily acccording to
2d3a210.

By doubling this timeout we hope to keep the connection alive when
performing the very heavy and chatty DLC-related protocols.

lightning-background-processor/src/lib.rs

@@ -94,7 +94,7 @@ const FRESHNESS_TIMER: u64 = 60;
 const FRESHNESS_TIMER: u64 = 1;
 
 #[cfg(all(not(test), not(debug_assertions)))]
-const PING_TIMER: u64 = 10;
+const PING_TIMER: u64 = 20;
 /// Signature operations take a lot longer without compiler optimisations.
 /// Increasing the ping timer allows for this but slower devices will be disconnected if the
 /// timeout is reached.