[#949] metabase: fix metabase mode metric

It used to always show CLOSED regardless of actual mode.
Now metric represents actual metabase mode of operations.

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

pkg/local_object_storage/metabase/control.go

@@ -42,6 +42,7 @@ func (db *DB) Open(_ context.Context, mode mode.Mode) error {
 	db.modeMtx.Lock()
 	defer db.modeMtx.Unlock()
 	db.mode = mode
+	db.metrics.SetMode(mode)
 
 	if mode.NoMetabase() {
 		return nil