#11 natTraversal variable not set on nat discovery

[Matt-SF]

The variable natTraversal in CLIInit is null even
when "nat discovery" is actively penetrating. This
can be seen by issuing "nat discovery" command
followed by "nat stat". CLI will report "NAT
traversal is not started" because natTraversal
variable is null. However, if "nat open" command is
issued, natTraversal is set and "nat stat" will
properly report the NAT info. The difference is
that "nat discovery" uses the variable
natDiscoveryClient to maintain the NAT info.

No hurry to fix, just confusing at first.