Fixed onos.py
Fixed onos.py

It now works also when no OpenFlow subsytem is loaded

Change-Id: If51f1ab654dad7c02a3f8744b53f4029abf1bd9f

osinstom/onos,kuujo/onos,opennetworkinglab/onos,kuujo/onos,osinstom/onos,gkatsikas/onos,osinstom/onos,osinstom/onos,opennetworkinglab/onos,oplinkoms/onos,kuujo/onos,kuujo/onos,opennetworkinglab/onos,osinstom/onos,oplinkoms/onos,gkatsikas/onos,opennetworkinglab/onos,kuujo/onos,kuujo/onos,oplinkoms/onos,gkatsikas/onos,oplinkoms/onos,kuujo/onos,gkatsikas/onos,oplinkoms/onos,opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos,gkatsikas/onos,oplinkoms/onos,oplinkoms/onos