fix: Improve error message for invalid version/backend format (#6149)

* fix: Improve error message for invalid version/backend format

This commit changes the error message displayed when the `version_backend` configuration is invalid. The new message is more user-friendly and suggests a simple solution, such as restarting the application, which is more helpful to the user than the previous technical error message.

* fix typo

extensions/llamacpp-extension/src/index.ts

@@ -1165,7 +1165,7 @@ export default class llamacpp_extension extends AIEngine {
     const [version, backend] = cfg.version_backend.split('/')
     if (!version || !backend) {
       throw new Error(
-        `Invalid version/backend format: ${cfg.version_backend}. Expected format: <version>/<backend>`
+        "Initial setup for the backend failed due to a network issue. Please restart the app!"
       )
     }