migration to python3 (#1)

Change-Id: I964b75c1316b7711cde905c6e98ea027a8557047
Signed-off-by: peusterm <manuel.peuster@uni-paderborn.de>
diff --git a/src/emuvim/api/sonata/dummygatekeeper.py b/src/emuvim/api/sonata/dummygatekeeper.py
index ea9a76e..f9af3b6 100755
--- a/src/emuvim/api/sonata/dummygatekeeper.py
+++ b/src/emuvim/api/sonata/dummygatekeeper.py
@@ -87,7 +87,7 @@
     r = list()
     for net in range(base, base + subnet_size):
         subnet = "{0}.{1}.0/{2}".format(prefix, net, mask)
-        r.append(ipaddress.ip_network(unicode(subnet)))
+        r.append(ipaddress.ip_network(subnet))
     return r