### 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
if (da->file_exists(basepath + "_start.ps1")) { \
			da->remove(basepath + "_start.ps1");        \
		}                                               \
		if (da->file_exists(basepath + "_clean.ps1")) { \
			da->remove(basepath + "_clean.ps1");        \
		}                                               \
		return m_err;                                   \
	}                                                   \
	((void)0)
	if (ep.step(TTR("Exporting project..."), 1)) {
		return ERR_SKIP;
	}
	Error err = export_project(p_preset, true, basepath + ".zip", p_debug_flags);
	if (err != OK) {
		DirAccess::remove_file_or_error(basepath + ".zip");
		return err;
	}
	String cmd_args;
	{
		Vector<String> cmd_args_list;
		gen_debug_flags(cmd_args_list, p_debug_flags);
		for (int i = 0; i < cmd_args_list.size(); i++) {
			if (i != 0) {
				cmd_args += " ";
			}
			cmd_args += cmd_args_list[i];
		}
	}
	const bool use_remote = (p_debug_flags & DEBUG_FLAG_REMOTE_DEBUG) || (p_debug_flags & DEBUG_FLAG_DUMB_CLIENT);
	int dbg_port = EditorSettings::get_singleton()->get("network/debug/remote_port");