light-node: can't initialise with header at height 1

[xla]

An attempt to init with the header at height 1 fails.

Potentially reproducible with:

• run a tendermint full node
• curl -X GET "http://localhost:26657/block?height=1” -H "accept: application/json"
• deserialise in Rust and investigate why header.hash() != block_id.hash

Potential causes:

• latest 0.33 changed something
• a potential bug when one of the last_ fields is not present in

tendermint-rs/tendermint/src/lite_impl/header.rs

Lines 28 to 58 in 142796b

	fn hash(&self) -> Hash {
	// Note that if there is an encoding problem this will
	// panic (as the golang code would):
	// https://github.com/tendermint/tendermint/blob/134fe2896275bb926b49743c1e25493f6b24cc31/types/block.go#L393
	// https://github.com/tendermint/tendermint/blob/134fe2896275bb926b49743c1e25493f6b24cc31/types/encoding_helper.go#L9:6
	let mut fields_bytes: Vec<Vec<u8>> = Vec::with_capacity(16);
	fields_bytes.push(AminoMessage::bytes_vec(&ConsensusVersion::from(
	&self.version,
	)));
	fields_bytes.push(bytes_enc(self.chain_id.as_bytes()));
	fields_bytes.push(encode_varint(self.height.value()));
	fields_bytes.push(AminoMessage::bytes_vec(&TimeMsg::from(self.time)));
	fields_bytes.push(
	self.last_block_id
	.as_ref()
	.map_or(vec![], |id| AminoMessage::bytes_vec(&BlockId::from(id))),
	);
	fields_bytes.push(self.last_commit_hash.as_ref().map_or(vec![], encode_hash));
	fields_bytes.push(self.data_hash.as_ref().map_or(vec![], encode_hash));
	fields_bytes.push(encode_hash(&self.validators_hash));
	fields_bytes.push(encode_hash(&self.next_validators_hash));
	fields_bytes.push(encode_hash(&self.consensus_hash));
	fields_bytes.push(bytes_enc(&self.app_hash));
	fields_bytes.push(self.last_results_hash.as_ref().map_or(vec![], encode_hash));
	fields_bytes.push(self.evidence_hash.as_ref().map_or(vec![], encode_hash));
	fields_bytes.push(bytes_enc(self.proposer_address.as_bytes()));
	Hash::Sha256(simple_hash_from_byte_vectors(fields_bytes))
	}
	}