Update default configuration for revoked HTLC clean-up

The default configuration for removing old rows containing revoked HTLC
data after a channel close was too slow and inadequate for most nodes.
We update it to use smaller batches without a much shorter interval.

Thanks @DerEwige for providing data about their experiments.

Fixes #3211

Author: t-bast

eclair-core/src/main/resources/reference.conf

@@ -584,9 +584,10 @@ eclair {
     // down the node, we delete those rows in batches at regular intervals.
     revoked-htlc-info-cleaner {
       // Number of rows to delete per batch: a higher value will clean up the DB faster, but may have a higher impact on performance.
-      batch-size = 50000
+      batch-size = 500
       // Frequency at which batches of rows are deleted: a lower value will clean up the DB faster, but may have a higher impact on performance.
-      interval = 15 minutes
+      // If you are frequently closing or splicing channels, you may want to increase the default interval if you're seeing IO performance issues.
+      interval = 1 seconds
     }
   }