SkylineWebcams extractor was not working.
Here are the list of changes to make it work:
1. Update the regex to extract the stream URL from the webpage.
In the webpage there is just a variable in the form `livee.m3u8?a=<id>`.
The usage of that link by appending it to
`https://hd-auth.skylinewebcams.com/` do not work. The solution was
to extract just the `?a=<id>` area and appending it to
`https://hd-auth.skylinewebcams.com/live.m3u8`.
The extractor works properly.
2. Updated `_TEST` with a new `url`. The old one was disabled.
It solves #28873.
