Loader: Fixed crash when canceling async loading of model
Loader: Fixed crash when canceling async loading of model

        - Clean up the _loader after we clean up the requests,
        not before that

Signed-off-by: deflected <4e8b39f4fad01cf7ba570fbff685e6b412438ff4@users.noreply.github.com>

chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d