KCC: unconnected graph test

KCC: unconnected graph test

Uses a unconnected 5 DC single site database to test Douglas Bagnalls
patch which corrected a mix up between a str and an object which caused
infinite recursion and a method call on a None type.

This test patch originally triggered an edge case bug. This bug is
triggered by code to create additional edges which normally never ran.
In normal cases, the leftover connections made during a join would
prevent these additional edges from being created.

Signed-off-by: Clive Ferreira <cliveferreira@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>