Search only in the niffilemanager for nif files
When we load a nif, we first search into the vfs to open the stream but we didn't use this stream as we have a special case for nif and we load the nif from the stream searched from the niffilemanager
When we load a nif, we first search into the vfs to open the stream but we didn't use this stream as we have a special case for nif and we load the nif from the stream searched from the niffilemanager