Fix compatibility issue with Kodi 20

[gigiquery]

Fix compatibility issue with Kodi 20

GHI (If applicable): #

Description:

Fixes #369 #380

Checklist:

• [x] I have based this PR against the develop branch

[IsaacChapman]

Just to confirm, I was able to get the Plex add-on for Kodi 20 to work by installing and starting SimpleSSHD and copying over the modified signal.py file from this PR to the TV with:

ANDROID_TV_IP_ADDRESS=<specify-android-tv-ip-address-here>
scp -P 2222 signal.py user@${ANDROID_TV_IP_ADDRESS}:/storage/emulated/0/Android/data/org.xbmc.kodi/files/.kodi/addons/script.plex/lib/_included_packages/plexnet/signalslot/signal.py

[cyr06]

Works nice thanks !

[HATT0R1HANZ0]

Nice one, thanks :)