Merge branch 'zhiyuanliang/startup-timeout' of https://github.com/Azure/AppConfiguration-JavaScriptProvider into zhiyuanliang/secret-refresh

Author: zhiyuanliang-ms

src/ConfigurationClientManager.ts

@@ -43,9 +43,6 @@ export class ConfigurationClientManager {
     #lastFallbackClientUpdateTime: number = 0; // enforce to discover fallback client when it is expired
     #lastFallbackClientRefreshAttempt: number = 0; // avoid refreshing clients before the minimal refresh interval
 
-    // This property is public to allow recording the last successful endpoint for failover.
-    endpoint: URL;
-
     constructor (
         connectionStringOrEndpoint?: string | URL,
         credentialOrOptions?: TokenCredential | AzureAppConfigurationOptions,