partial commit to fix wallet utils

this commit provide a lot of changes in will-settings including export to ics calendar file.

wallet_util/bal_wallet_utils.py

@@ -1,10 +1,11 @@
 #!env/bin/python3
-from electrum.storage import WalletStorage
-import json
-from electrum.util import MyEncoder
-import sys
 import getpass
+import json
 import os
+import sys
+
+from electrum.storage import WalletStorage
+from electrum.util import MyEncoder
 
 default_fees = 100
 
@@ -26,9 +27,12 @@ def fix_will_settings_tx_fees(json_wallet):
 
 
 def uninstall_bal(json_wallet):
-    del json_wallet["will_settings"]
-    del json_wallet["will"]
-    del json_wallet["heirs"]
+    if "will_settings" in json_wallet:
+        del json_wallet["will_settings"]
+    if "will" in json_wallet:
+        del json_wallet["will"]
+    if "heirs" in json_wallet:
+        del json_wallet["heirs"]
     return True