A recent appveyor vm update broke the build of the berkeleydb vcpkg dependency, see #19839. The temporary resolution was to switch back to the previous appveyor vm.
This PR updates the pegged vcpkg commit ID to the most recent commit as of 31 Aug 2020. That commit ID has been tested against the latest appveyor vm and is able to build Bitcoin Core successfully.
The vcpkg bump includes a patch to the berkeleydb build config which allows it to be built on the latest appveyor vm.