[Bugfix] RGCN tutorial (#388)

* fix rgcn tutorial

* small fix

* upd

examples/pytorch/rgcn/model.py

@@ -41,7 +41,7 @@ class BaseRGCN(nn.Module):
     def build_input_layer(self):
         return None
 
-    def build_hidden_layer(self):
+    def build_hidden_layer(self, idx):
         raise NotImplementedError
 
     def build_output_layer(self):

tutorials/models/1_gnn/4_rgcn.py

@@ -232,8 +232,8 @@ class Model(nn.Module):
         i2h = self.build_input_layer()
         self.layers.append(i2h)
         # hidden to hidden
-        for idx in range(self.num_hidden_layers):
-            h2h = self.build_hidden_layer(idx)
+        for _ in range(self.num_hidden_layers):
+            h2h = self.build_hidden_layer()
             self.layers.append(h2h)
         # hidden to output
         h2o = self.build_output_layer()