Remove useless arguments to `load_graph_from_csv`

They had the default values.

gt_segmentation.py

@@ -26,7 +26,10 @@ import sys
 
 if len(sys.argv) != 2: sys.exit("Required argument: edgelist-file")
 print('Loading edgelist file...')
-g = graph_tool.load_graph_from_csv(sys.argv[1], skip_first=False, directed=True, hashed=True, eprop_names=['nl_cost_function'], csv_options={'delimiter': ' ', 'quotechar': '"'})
+g = graph_tool.load_graph_from_csv(sys.argv[1],
+                                   directed = True,
+                                   eprop_names = ['nl_cost_function'],
+                                   csv_options = {'delimiter': ' '}
 print('Loading done')