wallet_db: fix _convert_version_25 (bip70 expiration)

electrum/wallet_db.py

@@ -538,7 +538,7 @@ class WalletDB(JsonDB):
     def _convert_version_25(self):
         if not self._is_upgrade_method_needed(24, 24):
             return
-        # add 'type' feld to onchain requests
+        # add 'type' field to onchain requests
         requests = self.data.get('payment_requests', {})
         for k, r in list(requests.items()):
             if r.get('address') == k:
@@ -563,7 +563,7 @@ class WalletDB(JsonDB):
                     'type': PR_TYPE_ONCHAIN,
                     'amount': pr.get_amount(),
                     'bip70': data,
-                    'exp': pr.get_expiration_date(),
+                    'exp': pr.get_expiration_date() - pr.get_time(),
                     'id': pr.id,
                     'message': pr.get_memo(),
                     'outputs': [x.to_legacy_tuple() for x in pr.get_outputs()],