message: [mempool] config tweaks
  Closes:
diff: @@ -34,8 +34,8 @@ impl Default for MempoolConfig {
  capacity: 1_000_000,
  capacity_per_user: 100,
  default_failovers: 0,
  - system_transaction_timeout_secs: 86400,
  - system_transaction_gc_interval_ms: 180_000,
  + system_transaction_timeout_secs: 600,
  + system_transaction_gc_interval_ms: 60_000,
  }
  }
  }
  