ProxyJump doesn't work when jump server has underscore in name

### Checklist

- [x] Using latest version on the [App Store](http://itunes.apple.com/app/id1156707581)
- [x] Read the [docs](http://blink.sh/docs/)
- [x] Searched for [existing GitHub issues](https://github.com/blinksh/blink/issues)

### Configuration

Blink version: 17.2.2.868
iOS: 17.4.1
iPhone 13 Pro

Blink version: 17.3.0.895
iPadOS: 17.4.1
iPad Pro 11-inch (3rd gen, M1)

### Describe the bug

When I try to use a host that has an underscore in its name to proxy jump, I get an error message.
I managed to replicate this on my iPhone using the latest app store version and my iPad with the TestFlight version.

For example, with the following configuration:

```
Alias: host_jump
HostName: ...
Port: ...
User: ...
```

```
Alias: host
HostName: ...
Port: ...
User: ...
ProxyJump: host_jump
```

attempting to `ssh host` gives me the error message:

```
Error connecting to testvm. operationError(msg: "Failed to set option \'SSH_OPTIONS_PROXYJUMP\'")
```

However, if I change this to

```
Alias: hostjump
HostName: ...
Port: ...
User: ...
```

```
Alias: host
HostName: ...
Port: ...
User: ...
ProxyJump: hostjump
```

then I can connect as expected.

For what it's worth, if I use ProxyCommand instead like so:

```
Alias: host_jump
HostName: ...
Port: ...
User: ...
```

```
Alias: host
HostName: ...
Port: ...
User: ...
ProxyCommand: ssh -W %h:%p host_jump
```

then `ssh host` works just fine as well.

Start by reproducing the two configuration examples from the issue, using a ProxyJump host alias with an underscore and then the working ProxyCommand form. Trace the SSH_OPTIONS_PROXYJUMP failure and compare the parsed host aliases; done means ProxyJump connects successfully with the underscore-containing alias on the listed iOS configurations.

Written by the indexing model from the issue text.