[source-sftp] need to change csv seperator

### Connector Name

SFTP

### Connector Version

0.2.2

### What step the error happened?

None

### Relevant information

This connector do not implement
reader_options (delimiter) 

We are trying to read several csv files with ; as separator.

### Relevant log output

```shell

```

### Contribute

- [ ] Yes, I want to contribute