Fix bad initializer

plugins/btchipwallet.py

@@ -46,7 +46,6 @@ class Plugin(BasePlugin):
         BasePlugin.__init__(self, gui, name)
         self._is_available = self._init()
         self.wallet = None        
-        self.signing = False
         electrum.wallet.wallet_types.append(('hardware', 'btchip', _("BTChip wallet"), BTChipWallet))
 
 
@@ -107,6 +106,7 @@ class BTChipWallet(NewWallet):
         self.client = None
         self.mpk = None
         self.device_checked = False
+        self.signing = False
 
     def give_error(self, message, clear_client = False):
         if not self.signing: