Commit 24b7cfc8 applied changes related to nullability as declared
by gir. One consequence was that some functions signature ended up
requiring users to pass `Some(val)` when they could use `val`
before.
This commit applies changes on `gstreamer-rs` which, will honoring
the nullability stil allow users to pass `val` for the few affected
functions.
This commit also fixes the signature for `Element::request_new_pad`
which was updated upstream.
Allow specifying an endpoint to be used for S3 requests. This makes
it possible to use integrations providing object storage based on S3
API like MinIO.
When the endpoint-uri property is specified, the endpoint resolver to
use will be overridden when making S3 requests.