add last segment even when last duration is shorter than asked duration (needed for segment timeine and dash-ctx)
add last segment even when last duration is shorter than asked duration (needed for segment timeine and dash-ctx)

fix #233

canatella/gpac,canatella/gpac,canatella/gpac,canatella/gpac,canatella/gpac,canatella/gpac,canatella/gpac