Construct base classes in right order

Fixed #1632

plugins/keepkey/client.py

@@ -3,9 +3,9 @@ from ..trezor.clientbase import TrezorClientBase
 
 class KeepKeyClient(TrezorClientBase, ProtocolMixin, BaseClient):
     def __init__(self, transport, handler, plugin, hid_id):
-        TrezorClientBase.__init__(self, handler, plugin, hid_id, proto)
         BaseClient.__init__(self, transport)
         ProtocolMixin.__init__(self, transport)
+        TrezorClientBase.__init__(self, handler, plugin, hid_id, proto)
 
     def recovery_device(self, *args):
         ProtocolMixin.recovery_device(self, True, *args)

plugins/trezor/client.py

@@ -3,9 +3,9 @@ from clientbase import TrezorClientBase
 
 class TrezorClient(TrezorClientBase, ProtocolMixin, BaseClient):
     def __init__(self, transport, handler, plugin, hid_id):
-        TrezorClientBase.__init__(self, handler, plugin, hid_id, proto)
         BaseClient.__init__(self, transport)
         ProtocolMixin.__init__(self, transport)
+        TrezorClientBase.__init__(self, handler, plugin, hid_id, proto)
 
 
 TrezorClientBase.wrap_methods(TrezorClient)

plugins/trezor/clientbase.py

@@ -65,6 +65,7 @@ class GuiMixin(object):
 class TrezorClientBase(GuiMixin, PrintError):
 
     def __init__(self, handler, plugin, hid_id, proto):
+        assert hasattr(self, 'tx_api')  # ProtocolMixin already constructed?
         self.proto = proto
         self.device = plugin.device
         self.handler = handler