Wrong type for WireguardPeers.endpoint

Under sdbus_block.networkmanager.settings.datatypes, the WireguardPeers.endpoint is defined as an integer instead of a string.

```python
@dataclass
class WireguardPeers(NetworkManagerSettingsMixin):
 ...
 endpoint: Optional[int] = field(
 metadata={'dbus_name': 'endpoint', 'dbus_type': 's'},
 default=None,
 )
 ...
``