- add netcfg package to list of requirements
Reason: the /etc/protocols file is needed in IBS by packages importing python-eventlet as a build dependency, otherwise the following build time failure occurs:

File "/usr/lib/python2.7/site-packages/eventlet/support/dns/rdtypes/IN/WKS.py", line 23, in
_proto_tcp = socket.getprotobyname('tcp')
socket.error: protocol not found