Merge #628: src/lib.rs:update description of Miniscript link

10a17e3 src/lib.rs:update description of Miniscript link (@RandyMcMillan)

Pull request description:

ACKs for top commit:
  apoelstra:
    ACK 10a17e3

Tree-SHA512: f39d6658232eac6da41ea458039f851ca665015d77a9951a5d12cc0af716df956d806b4deb69c89d15bd34b5d79daa1767ff9ea0bb4b75da131a5d569044fbcf

Author: apoelstra

src/lib.rs

@@ -25,7 +25,7 @@
 //! thresholds) of signature requirements, hash preimage requirements, and
 //! timelocks.
 //!
-//! A [full description of Miniscript is available here](http://bitcoin.sipa.be/miniscript/miniscript.html).
+//! A [full description of Miniscript is available here](https://bitcoin.sipa.be/miniscript).
 //!
 //! Miniscript also admits a more human-readable encoding.
 //!