Only publish on Windows

Author: RehanSaeed

appveyor.yml

@@ -45,7 +45,7 @@ deploy:
     secure: aunGGWt32irQiOTX2wIO6e2Y5Ga0girA3xSUsmQv6E9d6ohHdbK5HJpXpmxW9QM3
   on:
     # Only publish on Windows
-    image: Visual Studio 2019
+    CI_WINDOWS: true
     # Only publish from the master branch
     branch: master
 # Publish NuGet packages
@@ -55,7 +55,7 @@ deploy:
     secure: 73eFUWSfho6pxCy1VRP1H0AYh/SFiyEREV+/ATcoj0I+sSH9dec/WXs6H2Jy5vlS
   on:
     # Only publish on Windows
-    image: Visual Studio 2019
+    CI_WINDOWS: true
     # Only publish from the master branch
     branch: master
     # Only publish if the trigger was a Git tag