update wallet format again, for keystore

plugins/trezor/plugin.py

@@ -20,10 +20,7 @@ from ..hw_wallet import HW_PluginBase
 TIM_NEW, TIM_RECOVER, TIM_MNEMONIC, TIM_PRIVKEY = range(0, 4)
 
 class TrezorCompatibleKeyStore(Hardware_KeyStore):
-
-    def load(self, storage, name):
-        self.xpub = storage.get('master_public_keys', {}).get(name)
-        self.derivation = storage.get('derivation')
+    hw_type = 'trezor'
 
     def get_derivation(self):
         return self.derivation