Send Initial message into interactive shell.

I'd like to formulate a shell command that opens the `wscat` interact shell and also runs a given command right after it connects.

Currently, if I send a payload with -x, it doesn't bring up the interactive shell.

For example:

```
> wscat -c <endpoint> -x "{Auth command}"

Connected (press CTRL+C to quit)
{AuthCommand}
> 
```