fix TypeError

[anis3]

No description provided.

[Gujal00]

Why is this required? there are no calls for get_url in the plugin

[anis3]

play a youtube video with smr link tester

Starting Kodi (18.9 (18.9.0) Git:20201023-0655c2c718). Platform: Windows NT x86 64-bit

Error Type: <type 'exceptions.TypeError'>
Error Contents: Can't instantiate abstract class YoutubeResolver with abstract methods get_url
Traceback (most recent call last):
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\plugin.video.smr_link_tester\default.py", line 286, in
sys.exit(main())
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\plugin.video.smr_link_tester\default.py", line 282, in main
url_dispatcher.dispatch(mode, queries)
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\plugin.video.smr_link_tester\resources\lib\url_dispatcher.py", line 95, in dispatch
self.func_registry[mode](*args, **kwargs)
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\plugin.video.smr_link_tester\default.py", line 194, in play_link
hmf = resolveurl.HostedMediaFile(url=link)
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\script.module.resolveurl\lib\resolveurl\hmf.py", line 85, in init
self.__resolvers = self.__get_resolvers(include_disabled, include_universal, include_popups)
File "C:\Users\xxx\AppData\Roaming\Kodi\addons\script.module.resolveurl\lib\resolveurl\hmf.py", line 113, in __get_resolvers
resolver_cache[klass] = klass()
TypeError: Can't instantiate abstract class YoutubeResolver with abstract methods get_url
-->End of Python script error report<--

[Gujal00]

Seems to happen only on Kodi 18, no idea why. Works fine on Kodi19 without this change.