Meshgrid indexing='ij' for PyTorch 1.10

Will not merge currently as breaks backwards compatibility.

models/yolo.py

@@ -74,7 +74,7 @@ def forward(self, x):
 
     def _make_grid(self, nx=20, ny=20, i=0):
         d = self.anchors[i].device
-        yv, xv = torch.meshgrid([torch.arange(ny).to(d), torch.arange(nx).to(d)])
+        yv, xv = torch.meshgrid([torch.arange(ny).to(d), torch.arange(nx).to(d)], indexing='ij')
         grid = torch.stack((xv, yv), 2).expand((1, self.na, ny, nx, 2)).float()
         anchor_grid = (self.anchors[i].clone() * self.stride[i]) \
             .view((1, self.na, 1, 1, 2)).expand((1, self.na, ny, nx, 2)).float()