Clear old custom name formats when database loaded

gramps/cli/grampscli.py

@@ -318,6 +318,7 @@ class CLIManager:
                 and self.dbstate.db.get_total() == 0):
             self.dbstate.db.set_researcher(owner)
 
+        name_displayer.clear_custom_formats()
         name_displayer.set_name_format(self.dbstate.db.name_formats)
         fmt_default = config.get('preferences.name-format')
         name_displayer.set_default_format(fmt_default)

gramps/gen/display/name.py

@@ -418,6 +418,11 @@ class NameDisplay:
         result = raw_data[_FIRSTNAME]
         return ' '.join(result.split())
 
+    def clear_custom_formats(self):
+        self.name_formats = {num: value
+                             for num, value in self.name_formats.items()
+                             if num >= 0}
+
     def set_name_format(self, formats):
 
         raw_func_dict = {