Update Zhenguo Niu's mailmap
Update Zhenguo Niu's mailmap

Using new email address.

Change-Id: I77190d0da0dbd4480ff03bcfe84540292cc81ea3

moshele/networking-mlnx-master,moshele/networking-mlnx,stackforge/networking-mlnx,openstack/networking-mlnx,openstack/networking-mlnx,stackforge/networking-mlnx