libupnp: update comment about broken MSVC build

cURL is now available as a subproject, but the build is still broken…

Author: benoit-pierre

ci_config.json

@@ -313,7 +313,7 @@
     "debian_packages": [
       "libcurl4-gnutls-dev"
     ],
-    "_comment": "libcurl is not available with MSVC CI",
+    "_comment": "broken (see https://github.com/mesonbuild/wrapdb/pull/1149#issuecomment-1712678549)",
     "build_on": {
       "windows": false
     }