ges-launcher: do not set rendering details too early
It looks like the _set_rendering_details call is superfluous in _startup(), as it will get called in run_pipeline.
The problem with calling it before timeline_set_user_options is that we are going to fail creating a smart profile if the user selected eg --track-types=video, as the get_smart_profile method compares the tracks in the asset with those on the timeline.
Reproduce with a video-only clip:
ges-launch-1.0 --track-types=video +clip file://$PWD/jelly.mp4
inpoint=15.0 -o foo.mp4 --smart-rendering