Re-remove libmagic install from travis config, it's no longer needed (#15157)
Re-remove libmagic install from travis config, it's no longer needed (#15157)


bqbn/addons-server,mozilla/addons-server,bqbn/addons-server,wagnerand/addons-server,wagnerand/addons-server,mozilla/addons-server,mozilla/olympia,eviljeff/olympia,diox/olympia,mozilla/addons-server,eviljeff/olympia,mozilla/addons-server,mozilla/olympia,eviljeff/olympia,diox/olympia,mozilla/olympia,eviljeff/olympia,diox/olympia,bqbn/addons-server,mozilla/olympia,bqbn/addons-server,wagnerand/addons-server,diox/olympia,wagnerand/addons-server