Change blockscan.com to counterpartychain.io

[unsystemizer]

As per https://github.com/CounterpartyXCP/counterwallet/issues/813

Issues:

• counterpartychain.io has a placeholder page for orders, so the page doesn't do much for now
• counterpartychain.io has no txInfo page. I created a /tx link but it's 404 (which not worse than blockscan.com until a placeholder page is created)
• http changed to https

[jdogresorg]

Already updated in https://github.com/CounterpartyXCP/counterwallet/pull/817