policy: allow disabling load balancing

policy: allow disabling load balancing

Load-balancing only makes sense where multiple APs are deployed in the
same area. Enabling load-balancing between APs in different rooms might
steer clients to APs with a much lower signal strength, resulting in
lower data rates and inefficient use of airtime.

Allow disabling load balancing by setting the threshold to 0.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: David Bauer <mail@david-bauer.net>