revert the unintentional removal of flush in the messages

Author: renetapopova

modules/ROOT/pages/database-internals/checkpointing.adoc

@@ -139,14 +139,14 @@ The following details the expected messages to appear in the _logs\debug.log_ up
 +
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 2023-05-28 13:08:51.603+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for tx count threshold" @ txId: 118 checkpoint started...
-2023-05-28 13:08:51.669+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for tx count threshold" @ txId: 118 checkpoint completed in 66ms. Checkpoint flushed 74 pages (7% of total available pages), in 58 IOs. Checkpoint performed with IO limit: 789 IOPS, paused in total 0 times(0 millis). Average checkpoint : 592.0KiB/s.
+2023-05-28 13:08:51.669+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for tx count threshold" @ txId: 118 checkpoint completed in 66ms. Checkpoint flushed 74 pages (7% of total available pages), in 58 IOs. Checkpoint performed with IO limit: 789 IOPS, paused in total 0 times(0 millis). Average checkpoint flush speed: 592.0KiB/s.
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 * Checkpoint when `db.checkpoint=continuous`:
 +
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 2023-05-28 13:17:21.927+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for continuous threshold" @ txId: 171 checkpoint started...
-2023-05-28 13:17:21.941+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for continuous threshold" @ txId: 171 checkpoint completed in 13ms. Checkpoint flushed 74 pages (7% of total available pages), in 58 IOs. Checkpoint performed with IO limit: 789 IOPS, paused in total 0 times(0 millis). Average checkpoint : 592.0KiB/s.
+2023-05-28 13:17:21.941+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Scheduled checkpoint for continuous threshold" @ txId: 171 checkpoint completed in 13ms. Checkpoint flushed 74 pages (7% of total available pages), in 58 IOs. Checkpoint performed with IO limit: 789 IOPS, paused in total 0 times(0 millis). Average checkpoint flush speed: 592.0KiB/s.
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 * Checkpoint as a result of database shutdown: