fix update detection by using requests library over urllib

[axu2]

The update utility stopped working for me until i changed this.

Was getting this error

urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1002)>

• related last version check #518

[axu2]

@catsout heads up to add requests to the flatpak.

[catsout]

@axu2 Better to add this requirement to setup.py.

[axu2]

@catsout Done

• 7eb9853

[winstonma]

@axu2 Not sure if it is related but the latest flatpak version doesn't work. Thanks for checking

$ flatpak run io.github.ciromattia.kcc
Traceback (most recent call last):
  File "/app/bin/kcc", line 33, in <module>
    sys.exit(load_entry_point('KindleComicConverter==5.6.5', 'gui_scripts', 'kcc')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/lib/python3.11/site-packages/kindlecomicconverter/startup.py", line 29, in start
    from . import KCC_gui
  File "/app/lib/python3.11/site-packages/kindlecomicconverter/KCC_gui.py", line 28, in <module>
    import requests
ModuleNotFoundError: No module named 'requests'

Edit by axu2: @catsout

[catsout]

Seems with --root arg，python setup.py will not check dependencies.
I already added this requirement, wait for flathub's update.