fix webextension support

Author: ProgrammerIn-wonderland

product.json

@@ -8,7 +8,7 @@
     "extensionsGallery": {
       "serviceUrl": "https://open-vsx.org/vscode/gallery",
       "itemUrl": "https://open-vsx.org/vscode/item",
-      "resourceUrlTemplate": "https://openvsxorg.blob.core.windows.net/resources/{publisher}/{name}/{version}/{path}"
+      "resourceUrlTemplate": "https://open-vsx.org/vscode/asset/{publisher}/{name}/{version}/Microsoft.VisualStudio.Code.WebResources/{path}"
     },
     "extensionEnabledApiProposals": {
       "vscode.vscode-web-playground": [