[datasets] removed unnecessary stuff in Multi-PIE Dataset class

bob/learn/pytorch/datasets/multipie.py

@@ -81,9 +81,6 @@ class MultiPIEDataset(Dataset):
     else:
       c_set = db.clients()
 
-    ids = [client.id for client in c_set]
-    ids = sorted(ids, key=int)  
-
     # filename and pose label are dependent on the camera
     for camera in sorted(db.camera_names()):