import sdk for cloud fails to generate wildcard path

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

Create a data folder like below:

```
folder1/db1.t1.0.csv
folder1/db1.t1.1.csv.gz
folder1/db1.t2.0.csv
folder1/db1.t2.0.csv
folder2/.....
```

And execute `GetTableMetas`

### 2. What did you expect to see? (Required)

Get all table metas.

### 3. What did you see instead (Required)

Failed to get meta due to `generateWildcardPath` failure.

### 4. What is your TiDB version? (Required)

master