Upgrade PyTorch 0.4.0+ compatible initialization API

Author: d-li14

layers/modules/l2norm.py

@@ -14,7 +14,7 @@ def __init__(self,n_channels, scale):
         self.reset_parameters()
 
     def reset_parameters(self):
-        init.constant(self.weight,self.gamma)
+        init.constant_(self.weight,self.gamma)
 
     def forward(self, x):
         norm = x.pow(2).sum(dim=1, keepdim=True).sqrt()+self.eps