[#948] metrics: Set actual value for shard_id after restart

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

pkg/local_object_storage/engine/writecache.go

@@ -145,6 +145,10 @@ type writeCacheMetrics struct {
 	metrics metrics.WriteCacheMetrics
 }
 
+func (m *writeCacheMetrics) SetShardID(id string) {
+	m.shardID = id
+}
+
 func (m *writeCacheMetrics) Get(d time.Duration, success bool, st writecache.StorageType) {
 	m.metrics.AddMethodDuration(m.shardID, "Get", success, d, st.String())
 }