Fix torchscript issue with legacy tnt

Author: rwightman

timm/models/tnt.py

@@ -103,6 +103,7 @@ def __init__(
         if self.legacy:
             self.norm1_proj = norm_layer(dim)
             self.proj = nn.Linear(dim * num_pixel, dim_out, bias=True)
+            self.norm2_proj = None
         else:
             self.norm1_proj = norm_layer(dim * num_pixel)
             self.proj = nn.Linear(dim * num_pixel, dim_out, bias=False)
@@ -135,7 +136,7 @@ def forward(self, pixel_embed, patch_embed):
         pixel_embed = pixel_embed + self.drop_path(self.mlp_in(self.norm_mlp_in(pixel_embed)))
         # outer
         B, N, C = patch_embed.size()
-        if self.legacy:
+        if self.norm2_proj is None:
             patch_embed = torch.cat([
                 patch_embed[:, 0:1],
                 patch_embed[:, 1:] + self.proj(self.norm1_proj(pixel_embed).reshape(B, N - 1, -1)),