For CI - use new AppVeyor feature to skip MinGW cache for VS Ci build.

.appveyor.yml

@@ -44,6 +44,9 @@ environment:
     secure: JgsjFoVAP5yjNxyS/+S+4byhtnTKCWfI3bkCmHws3P1MwSaUS5+0C6WV1pHIJTVW00Qvo3+JsgVqMYUJ7fo2m/bXvUPNCoSa4BifXZlS6bE=
   SF_API:
     secure: cc1q9CXo5BwIYqtgigHpkCGG90zEVM45xx/YzXTOjVp512oQNUzTJq0AmxEYXP78
+# VS build actually does not need MinGW compiler toolchains so prevent its restoration and update check
+  APPVEYOR_CACHE_SKIP_RESTORE: true
+  APPVEYOR_CACHE_SKIP_SAVE: true
 # Using neither-in-nor-out-of-source (Urho3D-legacy) build tree when on AppVeyor; using out-of-source (and in-the-source) build tree when on Travis-CI for test coverage
   build_tree: Build
   config: Release