trezor: raise and catch BaseException in signing

plugins/btchipwallet.py

@@ -322,8 +322,10 @@ class BTChipWallet(NewWallet):
         return b64encode(chr(27 + 4 + (signature[0] & 0x01)) + r + s) 
 
     def sign_transaction(self, tx, keypairs, password):
-        if tx.error or tx.is_complete():
+        if tx.is_complete():
             return
+        if tx.error:
+            raise BaseException(tx.error)
         self.signing = True        
         inputs = []
         inputsPaths = []