### 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
String user_arg = user_args[i].strip_edges();
		if (!user_arg.is_empty()) {
			args.push_back(user_arg);
		}
	}
#ifndef WINDOWS_ENABLED
	args.push_back("-in");
#endif
	args.push_back(p_path);
#ifndef WINDOWS_ENABLED
	args.push_back("-out");
	args.push_back(p_path + "_signed");
#endif
	String str;
	Error err = OS::get_singleton()->execute(signtool_path, args, &str, nullptr, true);
	if (err != OK || (str.find("not found") != -1) || (str.find("not recognized") != -1)) {
#ifndef WINDOWS_ENABLED
		add_message(EXPORT_MESSAGE_WARNING, TTR("Code Signing"), TTR("Could not start signtool executable. Configure signtool path in the Editor Settings (Export > Windows > signtool), or disable \"Codesign\" in the export preset."));
#else
		add_message(EXPORT_MESSAGE_WARNING, TTR("Code Signing"), TTR("Could not start osslsigncode executable. Configure signtool path in the Editor Settings (Export > Windows > osslsigncode), or disable \"Codesign\" in the export preset."));
#endif
		return err;
	}
	print_line("codesign (" + p_path + "): " + str);
#ifndef WINDOWS_ENABLED
	if (str.find("SignTool Error") != -1) {
#else
	if (str.find("Failed") != -1) {
#endif
		add_message(EXPORT_MESSAGE_WARNING, TTR("Code Signing"), vformat(TTR("Signtool failed to sign executable: %s."), str));