This update for dnscrypt-proxy fixes the following issues:

- Update to version 2.1.7
  * Reintroduces support for XSalsa20 enryption in DNSCrypt,
    which was removed in 2.1.6. Unfortunately, a bunch of servers still
    only support that encryption system.
  * Added check for lying resolvers was added for DNSCrypt, similar to 
    the one that was already present for DoH and ODoH.

- Update to version 2.1.6
  * Forwarding: in the list of servers for a zone, the `$BOOTSTRAP`
    keyword can be included as a shortcut to forward to the bootstrap
    servers. And the `$DHCP` keyword can be included to forward to the
    DNS resolvers provided by the local DHCP server. Based on work by YX
    Hao, thanks! DHCP forwarding should be considered experimental and my
    not work on all operating systems. A rule for a zone can mix and
    match multiple forwarder types, such as `10.0.0.1,10.0.0.254,$DHCP,
    192.168.1.1,$BOOTSTRAP`. Note that this is not implemented for
    captive portals yet.
  * Lying resolvers are now skipped, instead of just printing an error.
    This doesn't apply to captive portal and forwarding entries, which
    are the only reasonable use case for lying resolvers.
  * Support for XSalsa20 in DNSCrypt has been removed. This was not
    documented, and was supserseded by XChaCha20 in 2016.
  * Source files are now fetched with compression.
  * DNS64: compatibility has been improved.
  * Forwarding: the root domain (`.`) can now be forwarded.
  * The ARC caching algorithm has been replaced by the SIEVE algorithm.
  * Properties of multiple servers are now updated simultaneously. The
    concurrency level can be adjusted with the new
    `cert_refresh_concurrency` setting. Contributed by YX Hao.
  * MSI packages for DNSCrypt can now easily be built.
  * New command-line flag: `-include-relays` to include relays in `-list`
    and `-list-all`.
  * Support for DNS extended error codes has been added.
  * Documentation updates, bug fixes, dependency updates.