update windows again

.gitlab-ci.yml

 image: "ubuntu:xenial"
 stages:
         - linux
+        - windows
 
 build:
 
@@ -24,7 +25,7 @@ build:
                 - curl https://data.kitware.com/api/v1/file/5877a2498d777f05f44b13fb/download -o castxml.tar.gz && tar -xzf castxml.tar.gz
                 - python3 -m pip install -r requirements.txt
 
-image: "mcr.microsoft.com/windows/nanoserver:1909"
+image: "mcr.microsoft.com/windows/nanoserver:1903"
 stages:
         - windows