[indexer.client] Update extensions.json

.vscode/extensions.json

 {
     // See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
     // Extension identifier format: ${publisher}.${name}. Example: vscode.csharp
-  
+
     // List of extensions which should be recommended for users of this workspace.
     "recommendations": [
       "dbaeumer.vscode-eslint",