Blacklist BSS on first failure if only a single network is enabled

Blacklist BSS on first failure if only a single network is enabled

The special case of requiring blacklisting count to be 2 or higher
is only needed when more than a single network is currently enabled.
As such, we should not do that when only a single network is enabled.
This make the station more likely to follow network side load
balancing attempts where the current AP may disassociate us with
an assumption that we would move to another AP.