fix typo in dynamic_inventory.py
fix typo in dynamic_inventory.py

fix typo main_netowrk to main_network in dynamic_inventory.py

Change-Id: Ic15ddce2b12afdea7f1e983d064ad90ef09d3a65
Closes-Bug: #1517047

mancdaz/openstack-ansible,Logan2211/openstack-ansible,cfarquhar/openstack-ansible,bunchc/openstack-ansible,yanyao/openstack-ansible,BjoernT/os-ansible-deployment,mancdaz/openstack-ansible,yanyao/newton,os-cloud/os-ansible-deployment,openstack/openstack-ansible,jpmontez/openstack-ansible,stackforge/os-ansible-deployment,major/openstack-ansible,stackforge/os-ansible-deployment,BjoernT/openstack-ansible,yanyao/openstack-deployment-liberty,cloudnull/os-ansible-deployment,yanyao/openstack-deployment-liberty,BjoernT/os-ansible-deployment,major/os-ansible-deployment,robb-romans/openstack-ansible,git-harry/os-ansible-deployment,openstack/openstack-ansible,weezer/openstack-ansible,BjoernT/os-ansible-deployment,cfarquhar/openstack-ansible,major/os-ansible-deployment,open-switch/infra_openstack-ansible,jpmontez/openstack-ansible,git-harry/os-ansible-deployment,robb-romans/openstack-ansible,bunchc/openstack-ansible,mrda/openstack-ansible,jpmontez/os-ansible-deployment,BjoernT/openstack-ansible,open-switch/infra_openstack-ansible,weezer/openstack-ansible,cloudnull/os-ansible-deployment,yanyao/newton,jpmontez/os-ansible-deployment,Logan2211/openstack-ansible,major/openstack-ansible,git-harry/os-ansible-deployment,jpmontez/openstack-ansible,yanyao/openstack-deployment-liberty,yanyao/openstack-ansible,mrda/openstack-ansible,open-switch/infra_openstack-ansible,jpmontez/os-ansible-deployment,os-cloud/os-ansible-deployment,mrda/openstack-ansible