fix(crypto): add protections for decryption

UI/PreferencesUI/UIxPreferences.m

@@ -1624,6 +1624,8 @@ static NSArray *reminderValues = nil;
                           [oldAccount objectForKey: @"name"], [exception reason]];
                   decryptedPassword = @"";
                 }
+                else if(!decryptedPassword)
+                  [self errorWithFormat:@"No exception but decrypted password is empty for account %@",[oldAccount objectForKey: @"name"]];
                 else
                   password = decryptedPassword;
               NS_HANDLER