Object|Boolean, An object with sync status data or FALSE, when not syncing:
startingBlock: QUANTITY - The block at which the import started (will only be reset, after the sync reached his head)
currentBlock: QUANTITY - The current block, same as eth_blockNumber
highestBlock: QUANTITY - The estimated highest block
// Result{"id":1,"jsonrpc":"2.0","result": { startingBlock: '0x384', currentBlock: '0x386', highestBlock: '0x454' }}// Or when not syncing{"id":1,"jsonrpc":"2.0","result":false}