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,
    )
   ...
``