fix the blockheight in bifrost

Recently there is a change in bifrost to bundle all the tx observed during a period time, and send it to thorchain as one transaction to increase the throughput , which messed up the blockheight a bit

Binance is doing about 1 block per sec, while thorchain is 5s per block , so if we consistently send large amount of swap request on binance chain , then bifrost might bundle all the tx in 5 blocks into one tx, as a result of that , the blockheight in the inbound tx to thorchain, will all be marked as the same block height , which is not corret.