Add magnet link for 0.17.0 release
Add magnet link for 0.17.0 release

Add magnet link for 0.17.0 release. Also bump the release date to today.

Tree-SHA512: f6576a5fa551db5c495ce86f07a6862af4111c397a31c8e3449c3c2bec07dc73271d4ff1946ac9cb5d43c20e6fb56cb83d23a8e4d58ac7e84556c8c74d409601

bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org