Properly render Neutron segmentation type and L23 provider

- previsous fix hided Neutron segmentation type (GRE, VLAN) when option
  "Neutron with GRE segmentation" or "Neutron with VLAN segmentation"
  was used.  Return previous behaviour back.
- NSX is a special case.  It segmentation type can by dynamically
  changed on Settings tab by changing NSX connector type (STT, GRE,
  Bridge, etc).  Just for now hide segmentation type for it, title on
  Networks tab would look like "Neutron with NSX", no matter what
  connector type was chosen.
- while here pull <span> out of if statement

Change-Id: I8b207e7b60d988884f151fefde600dea64976821
Closes-bug: #1347687
Merge "Properly render Neutron segmentation type and L23 provider"