hww: fix HardwareClientBase not having reference to plugin

it was incorrectly documented that it did (previously only for some plugins)

electrum/plugins/trezor/clientbase.py

@@ -40,10 +40,10 @@ MESSAGES = {
 
 class TrezorClientBase(HardwareClientBase, Logger):
     def __init__(self, transport, handler, plugin):
+        HardwareClientBase.__init__(self, plugin=plugin)
         if plugin.is_outdated_fw_ignored():
             TrezorClient.is_outdated = lambda *args, **kwargs: False
         self.client = TrezorClient(transport, ui=self)
-        self.plugin = plugin
         self.device = plugin.device
         self.handler = handler
         Logger.__init__(self)