fix crash with fmp4demux when the init is not constructed with a movieFileMap
fix crash with fmp4demux when the init is not constructed with a movieFileMap

RodolpheFouquet/gpac,rbouqueau/gpac,emmanouil/gpac,aymanelyaagoubi/gpac,porcelijn/gpac,RodolpheFouquet/gpac,emmanouil/gpac,nguyen-viet-thanh-trung/gpac,rbouqueau/gpac,gpac/gpac,aymanelyaagoubi/gpac,ARSekkat/gpac,rauf/gpac,emmanouil/gpac,rbouqueau/gpac_brew_travis,gpac/gpac,rbouqueau/gpac_brew_travis,gpac/gpac,ARSekkat/gpac,RodolpheFouquet/gpac,aymanelyaagoubi/gpac,ARSekkat/gpac,nguyen-viet-thanh-trung/gpac,rbouqueau/gpac,rbouqueau/gpac,porcelijn/gpac,gpac/gpac,aymanelyaagoubi/gpac,gpac/gpac,RodolpheFouquet/gpac,aymanelyaagoubi/gpac,nguyen-viet-thanh-trung/gpac,rauf/gpac,nguyen-viet-thanh-trung/gpac,rbouqueau/gpac_brew_travis,emmanouil/gpac,gpac/gpac,rauf/gpac,rbouqueau/gpac_brew_travis,RodolpheFouquet/gpac,nguyen-viet-thanh-trung/gpac,ARSekkat/gpac,emmanouil/gpac,nguyen-viet-thanh-trung/gpac,porcelijn/gpac,rauf/gpac,emmanouil/gpac,ARSekkat/gpac,rbouqueau/gpac,porcelijn/gpac,gpac/gpac,gpac/gpac,aymanelyaagoubi/gpac,ARSekkat/gpac,porcelijn/gpac,rbouqueau/gpac,rbouqueau/gpac_brew_travis,rauf/gpac,RodolpheFouquet/gpac,rbouqueau/gpac_brew_travis,porcelijn/gpac,rbouqueau/gpac,rbouqueau/gpac,rauf/gpac