Remove unnecessary `lookup_allowed` method from media admin.
Remove unnecessary `lookup_allowed` method from media admin.

lewiscollard/cms,lewiscollard/cms,dan-gamble/cms,danielsamuels/cms,lewiscollard/cms,jamesfoley/cms,jamesfoley/cms,dan-gamble/cms,jamesfoley/cms,dan-gamble/cms,danielsamuels/cms,danielsamuels/cms,jamesfoley/cms