Fix BSRGAN Model loading.

        if not os.path.exists(filename) or filename is None:

            print("Unable to load %s from %s" % (self.model_path, filename))

            return None

        model = RRDBNet(in_nc=3, out_nc=3, nf=64, nb=23, gc=32, sf=2)  # define network

        print("Loading %s from %s" % (self.model_path, filename))

        model = RRDBNet(in_nc=3, out_nc=3, nf=64, nb=23, gc=32, sf=4)  # define network

        model.load_state_dict(torch.load(filename), strict=True)

        model.eval()

        for k, v in model.named_parameters():