[#725] writecache: Fix metric values

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/writecache/writecachebbolt/state.go

@@ -72,5 +72,6 @@ func (c *cache) initCounters() error {
 		return fmt.Errorf("could not read write-cache DB counter: %w", err)
 	}
 	c.objCounters.cDB.Store(inDB)
+	c.estimateCacheSize()
 	return nil
 }