fix FlatNetworkTestCase.test_get_instance_nw_info
fix FlatNetworkTestCase.test_get_instance_nw_info

Most of this function was bypassed and the
bypassed portion contained syntax errors.
So reneable the skipped branch and adjust to pass.

Change-Id: I364ccfbe5be5bc050ba0004133f353beed97fae7

n0ano/ganttclient