Try to keep python 2.7 compability until at least netBSD gets gtk2 support on python3

scripting.py

+from __future__ import print_function
 import os.path
 import sys
 

utils.py

 import networkx as nx
-import http.client
+import sys
+if (sys.version_info > (3, 0)):
+    import http.client as httplib
+else:
+    import httplib
 
 def reciprocity(G):
     """Calculate reciprocity of graph, i.e. the ratio of the edges in
@@ -73,7 +77,7 @@ def cap2str(capacity):
 
 def read_linkloads(G, host, url):
 
-    conn = http.client.HTTPConnection(host)
+    conn = httplib.HTTPConnection(host)
     conn.request("GET", url)
     r1 = conn.getresponse()
     if r1.status != 200: