package/ortp: bump version to 0.25.0
This version bump is needed by mediastreamer 2.12.1, the mediastreamer
bump is needed to provide support for ffmpeg 3.0.
Removed srtp option after srtp support was removed from ortp:
https://github.com/BelledonneCommunications/ortp/commit/5e37fa55f1f15f5896d69156e64cdc95a1ff68bf
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>