vs: Sometimes WindowsSDKVersion is unset
vs: Sometimes WindowsSDKVersion is unset

https://ci.appveyor.com/project/jpakkane/meson/build/2871/job/ti4qpoptd5tk19sn

jeandet/meson,thiblahute/meson,thiblahute/meson,pexip/meson,pexip/meson,MathieuDuponchelle/meson,fmuellner/meson,jpakkane/meson,aaronp24/meson,fmuellner/meson,pexip/meson,wberrier/meson,thiblahute/meson,aaronp24/meson,trhd/meson,mesonbuild/meson,trhd/meson,aaronp24/meson,thiblahute/meson,mesonbuild/meson,QuLogic/meson,fmuellner/meson,becm/meson,QuLogic/meson,jeandet/meson,pexip/meson,MathieuDuponchelle/meson,mesonbuild/meson,ernestask/meson,wberrier/meson,QuLogic/meson,becm/meson,becm/meson,fmuellner/meson,jpakkane/meson,wberrier/meson,pexip/meson,becm/meson,aaronp24/meson,fmuellner/meson,ernestask/meson,mesonbuild/meson,pexip/meson,trhd/meson,thiblahute/meson,ernestask/meson,fmuellner/meson,MathieuDuponchelle/meson,trhd/meson,mesonbuild/meson,trhd/meson,QuLogic/meson,jpakkane/meson,aaronp24/meson,trhd/meson,thiblahute/meson,QuLogic/meson,MathieuDuponchelle/meson,jeandet/meson,aaronp24/meson,pexip/meson,pexip/meson,aaronp24/meson,fmuellner/meson,MathieuDuponchelle/meson,thiblahute/meson,jeandet/meson,jpakkane/meson,jpakkane/meson,jpakkane/meson,ernestask/meson,becm/meson,jeandet/meson,aaronp24/meson,MathieuDuponchelle/meson,ernestask/meson,jpakkane/meson,ernestask/meson,jeandet/meson,mesonbuild/meson,jpakkane/meson,becm/meson,aaronp24/meson,MathieuDuponchelle/meson,mesonbuild/meson,jeandet/meson,trhd/meson,trhd/meson,jeandet/meson,becm/meson,trhd/meson,pexip/meson,QuLogic/meson,thiblahute/meson,fmuellner/meson,pexip/meson,becm/meson,fmuellner/meson,jpakkane/meson,QuLogic/meson,wberrier/meson,wberrier/meson,QuLogic/meson,thiblahute/meson,mesonbuild/meson,wberrier/meson,ernestask/meson,becm/meson,ernestask/meson,wberrier/meson,wberrier/meson,MathieuDuponchelle/meson,QuLogic/meson,mesonbuild/meson,jeandet/meson,becm/meson,ernestask/meson,MathieuDuponchelle/meson,mesonbuild/meson