Fix running errors

[elig0n]

1)

File ".../call_map/call_map/project_settings_module.py", line 4, in <module>
    from typing import List, GenericMeta, Any, Tuple, Optional, Dict, Iterable
ImportError: cannot import name 'GenericMeta' from 'typing' (/usr/lib/python3.9/typing.py)

hsolbrig/PyShEx#17 (comment)

2)

  File ".../call_map/call_map/gui.py", line 411, in CallList
    @QtCore.Slot(int, object)
AttributeError: module 'PyQt5.QtCore' has no attribute 'Slot'

https://stackoverflow.com/questions/50459672/attributeerror-module-pyqt5-qtcore-has-no-attribute-slot
https://www.riverbankcomputing.com/static/Docs/PyQt5/signals_slots.html#the-pyqtslot-decorator

[lgtm-com]

This pull request fixes 1 alert when merging ea445bd into 8f9b412 - view on LGTM.com

fixed alerts:

• 1 for Unused import