mpyp: Always use --check-untyped-defs

`mypy EDMarketConnector.py` was throwing a warning:

    By default the bodies of untyped functions are not checked, consider using --check-untyped-defs  [annotation-unchecked]

for some things.  Bizarrely including e.g.

    play_bad: bool = False

.mypy.ini

@@ -2,4 +2,8 @@
 follow_imports = skip
 ignore_missing_imports = True
 scripts_are_modules = True
+; Without this bare `mypy <file>` may get warnings for e.g.
+;   `<var> = <value>`
+; i.e. no typing info.
+check-untyped-defs = True
 ; platform = darwin