call super().__init__() for WalletFileException descendants,

qt: handle unfinished wallets when opened via File>Open (ref #8809)

electrum/gui/qt/__init__.py

@@ -352,6 +352,8 @@ class ElectrumGui(BaseElectrumGui, Logger):
                 pass  # open with wizard below
             except WalletRequiresUpgrade:
                 pass  # open with wizard below
+            except WalletUnfinished:
+                pass  # open with wizard below
             except Exception as e:
                 self.logger.exception('')
                 err_text = str(e) if isinstance(e, WalletFileException) else repr(e)

electrum/wallet_db.py

@@ -56,11 +56,13 @@ class WalletRequiresUpgrade(WalletFileException):
 
 class WalletRequiresSplit(WalletFileException):
     def __init__(self, split_data):
+        super().__init__()
         self._split_data = split_data
 
 
 class WalletUnfinished(WalletFileException):
     def __init__(self, wallet_db: 'WalletDB'):
+        super().__init__()
         self._wallet_db = wallet_db