Forces GStreamer to re-scan its plugin paths and update the default plugin registry.
Applications will almost never need to call this function, it is only
useful if the application knows new plugins have been installed (or old
ones removed) since the start of the application (or, to be precise, the
first call to
gst_init()) and the application wants to make use of any
newly-installed plugins without restarting the application.
Applications should assume that the registry update is neither atomic nor thread-safe and should therefore not have any dynamic pipelines running (including the playbin and decodebin elements) and should also not create any elements or access the GStreamer registry while the update is in progress.
Note that this function may block for a significant amount of time.