Minor: Correct Confusing Statment In /bin/block-chain/README.txt

[harding]

As pointed out on #bitcoin-dev IRC, the statement I wrote for /bin/block-chain/README.txt contains two confusions. For reference, here is the statement:

As of Bitcoin Core version 0.10.0 and later, the block chain bootstrap
torrent formerly hosted here is *slower* than a direct download using
the bitcoin P2P protocol & client.

1. The statement can be inferred to mean that Bitcoin Core can download blocks using the Bitcoin P2P protocol faster than a torrent client can download them using the BitTorrent protocol.
2. The use of Markdown-style asterisk emphasis (*emphasis*) looks like a footnote reference.

Here is a revised statement that is hopefully more clear.

As of Bitcoin Core version 0.10.0 and later, the block chain bootstrap
torrent hosted here takes more time to download and import than it would
to simply start Bitcoin Core and let it sync itself.

[saivann]

Updated

[harding]

@saivann thanks! Closing.