rxv discovery fails with invalid Location urls

[slyoldfox]

My Synology SRM sends back a LOCATION: http://:8000/ssdp/desc-DSM-bwlan0.xml header which is totally wrong.

The code fails with

requests.exceptions.InvalidURL: Invalid URL 'http://:8000/ssdp/desc-DSM-bwlan0.xml': No host supplied

[slyoldfox]

@wuub any chance you or another contributor could merge this and cut a release.
It’s breaking HA detection