[coreobj] in PyCoreNetIf: while creating interface-tlv's, handled the case when an interface has no mac-addr
[coreobj] in PyCoreNetIf: while creating interface-tlv's, handled the case when an interface has no mac-addr

Signed-off-by: Robert Wuttke <12e9293ec6b30c7fa8a0926af42807e929c1684f@benocs.com>

Benocs/core,Benocs/core,Benocs/core,Benocs/core,Benocs/core