Fix for svtplay

[vandmo]

Had to make this change to make it work with svtplay.se
Not sure if it is "standard" dash stuff though.

[dinandferro]

Can you add support tor streams that are protected by license to add the license?

[ForceGT]

Hey @dinandferro Look Here

You have a request object r which is sending a direct get request , you can modify it as you like
I have seen two use cases

1. The url which gives mpd has to be given some headers otherwise it returns 403, you can easily handle this use case
2. A license url parameter(as you mentioned) : This is nothing but a post request that has to be sent with a license challenge, the logic for whose generation is not known to me. I will get back as soon as I figure out how to generate a license challenge. Basically then you will send a post request to the server and you will get a binary response which is the license for the server