Update vcpkg checkout commit.

Previously vcpkg was relying on https://repo.msys2.org/mingw/i686/mingw-w64-i686-pkg-config-0.29.2-1-any.pkg.tar.xz which is no longer available. The vcpkg source has been updated to use http://repo.msys2.org/mingw/i686/mingw-w64-i686-pkg-config-0.29.2-2-any.pkg.tar.zst. This PR updates the commit ID used to checkout vcpkg for the updated URL.

Author: sipsorcery

.appveyor.yml

@@ -10,7 +10,7 @@ environment:
   QT_DOWNLOAD_URL: 'https://github.com/sipsorcery/qt_win_binary/releases/download/qt598x64_vs2019_v1681/qt598_x64_vs2019_1681.zip'
   QT_DOWNLOAD_HASH: '00cf7327818c07d74e0b1a4464ffe987c2728b00d49d4bf333065892af0515c3'
   QT_LOCAL_PATH: 'C:\Qt5.9.8_x64_static_vs2019'
-  VCPKG_TAG: '2020.11-1'
+  VCPKG_TAG: '75522bb1f2e7d863078bcd06322348f053a9e33f'
 install:
 # Disable zmq test for now since python zmq library on Windows would cause Access violation sometimes.
 # - cmd: pip install zmq