fixed 2 possible heap overflows (inc. #1088)
void stss_del(GF_Box *s)
{
	GF_SyncSampleBox *ptr = (GF_SyncSampleBox *)s;
	if (ptr == NULL) return;
	if (ptr->sampleNumbers) gf_free(ptr->sampleNumbers);
	gf_free(ptr);
}

void stss_del(GF_Box *s)
{
	GF_SyncSampleBox *ptr = (GF_SyncSampleBox *)s;
	if (ptr == NULL) return;
	if (ptr->sampleNumbers) gf_free(ptr->sampleNumbers);
	gf_free(ptr);
}
