Set ip_nonlocal_bind in namespace if it exists

Set ip_nonlocal_bind in namespace if it exists

Somewhere in the 3.19 kernel timeframe ip_nonlocal_bind was
changed to be a per-namespace attribute. To be backwards
compatible we need to try that first, then fall-back to
setting the one in the root namespace if it fails.

Closes-Bug: #1507078
Change-Id: I018e800bc8d4e85d067aaae865c9b04bf030c980