don't allow seeking out of bounds
don't allow seeking out of bounds

restrict range to [0,duration-1]
related to https://github.com/mangui/flashls/issues/413

vidible/vdb-flashls,vidible/vdb-flashls,mangui/flashls,fixedmachine/flashls,tedconf/flashls,codex-corp/flashls,neilrackett/flashls,neilrackett/flashls,fixedmachine/flashls,jlacivita/flashls,NicolasSiver/flashls,hola/flashls,mangui/flashls,hola/flashls,codex-corp/flashls,jlacivita/flashls,tedconf/flashls,NicolasSiver/flashls,clappr/flashls,clappr/flashls