Fix Windows postfix for changed release

Author: james-fossa

vendor_download.sh

@@ -87,7 +87,7 @@ case "$(uname -s)" in
     echo "Warn: Assuming $(uname -s) is Windows"
     ASSET_POSTFIX="windows.exe"
     THEMIS_ASSET_POSTFIX="windows-amd64"
-    FICUS_ASSET_POSTFIX="x86_64-windows.exe.zip"
+    FICUS_ASSET_POSTFIX="x86_64-pc-windows-msvc.zip"
     LERNIE_ASSET_POSTFIX="x86_64-windows.exe"
     CIRCE_ASSET_POSTFIX="x86_64-pc-windows-msvc"
     ;;