### Godot version

v4.0.beta.custom_build [d1e5903c6]

### System information

Arch Linux kernel 6.1.7-arch1-1 x86_64 OpenSSH 9.1p1-3

### Issue description

When using SSH remote deploy, if the extra args field is empty (the default) the ssh command is not executed with success because a single space is inserted in place of the extra args.

```
Creating temporary directory...
Executing: ssh -p 22  davi@192.168.1.50 mktemp -d
Exit code: 255, Output: ssh: Could not resolve hostname : Name or service not known

ssh: Could not resolve hostname : Name or service not known
```

If any valid argument is passed, the command is executed successfully, in the example below I duplicated the `-p 22`, which is ignored, to show that it is not a problem of the hostname passed.

```
Executing: ssh -p 22 -p 22 davi@192.168.1.50 mktemp -d
Exit code: 0, Output: /tmp/tmp.DwFObXBL2s
```

This is infuriating for when you have non-interactive authentication configured in ssh-agent and just the hostname is needed for the connection.
This occurs for both SSH and SCP.

### Steps to reproduce

1. Enable a project to deploy with ssh
2. Fill only the hostname
3. Try to deploy
4. See the error on the console

### Minimal reproduction project

N/A
ExportNotifier notifier(*this, p_preset, p_debug, p_path, p_flags);
	String src_pkg_name;
	EditorProgress ep("export", "Exporting for macOS", 3, true);
	if (p_debug) {
		src_pkg_name = p_preset->get("custom_template/debug");
	} else {
		src_pkg_name = p_preset->get("custom_template/release");
	}
	if (src_pkg_name.is_empty()) {
		String err;
		src_pkg_name = find_export_template("macos.zip", &err);
		if (src_pkg_name.is_empty()) {
			add_message(EXPORT_MESSAGE_ERROR, TTR("Prepare Templates"), TTR("Export template not d."));
			return ERR_FILE_NOT_FOUND;
		}
	}
	if (!DirAccess::exists(p_path.get_base_dir())) {
		add_message(EXPORT_MESSAGE_ERROR, TTR("Prepare Templates"), TTR("The given export path doesn't exist."));
		return ERR_FILE_BAD_PATH;
	}
	Ref<FileAccess> io_fa;
	zlib_filefunc_def io = zipio_create_io(&io_fa);
	if (ep.step(TTR("Creating app bundle"), 0)) {