Remove hardcoded username and password

[lostb1t]

Some providers do not have username and password arguments. This also allows setting other provider specific arguments if needed

[Gaisberg]

Hmm... We only use username and password peoviderconfig for the ones in the settings. Im pretty sure they all require authentication?

[lostb1t]

gestdown (or was it podnapisi) crashes with username and password password.

[Gaisberg]

If you look at the original code we loop over the providers in the settings file, not the default providers (including podnapisi and gestdown). The providers in the settings file require configurations and if the setting is enabled we append the provider along with the configuration to initialization of the subliminal class. Im not sure why you would be having configurations for providers outside of the providers that are supplied by the settings.

[lostb1t]

whats the reason for not having all providers in the settings in the first place?

[Gaisberg]

The default providers are enabled on subliminal by default so I didnt see a reason to add them.