mssdemux: Use gsturi structure to form fragment urls
We can use gst_uri_from_string_with_base () to join base url and the fragment url path.
The previous method of forming base url in update_base_url(), by looking for the string 'manifest' or 'Manifest' is insufficient. A query may include these string in their paths and thus an invalid base url string will be kept.
Moved from gst-plugins-bad!1502 (closed)