update error message

Author: linglingye001

azureappconfiguration/azureappconfiguration.go

@@ -721,7 +721,7 @@ func (azappcfg *AzureAppConfiguration) startupWithRetry(ctx context.Context, tim
 		// Wait for the backoff duration before retrying
 		select {
 		case <-startupCtx.Done():
-			return fmt.Errorf("startup context cancelled during backoff: %w", startupCtx.Err())
+			return fmt.Errorf("load from Azure App Configuration timed out: %w", startupCtx.Err())
 		case <-time.After(backoffDuration):
 			// Continue to next retry attempt
 		}

azureappconfiguration/failover_test.go

@@ -823,7 +823,7 @@ func TestStartupWithRetry_ContextCancelledDuringBackoff(t *testing.T) {
 	err := azappcfg.startupWithRetry(ctx, 10*time.Second, operation)
 
 	assert.Error(t, err)
-	assert.Contains(t, err.Error(), "startup context cancelled during backoff")
+	assert.Contains(t, err.Error(), "load from Azure App Configuration timed out: context canceled")
 }
 
 // Test startupWithRetry with default timeout when zero timeout provided