Fix ENABLE_NETWORK not to reconnect in disconnected state

Fix ENABLE_NETWORK not to reconnect in disconnected state

DISCONNECT followed by ENABLE_NETWORK ended up starting a scan for a new
connection due to wpa_supplicant_enable_one_network() setting
wpa_s->reassociate = 1. This was done regardless of wpa_s->disconnected
being 1 which should imply that wpa_supplicant should not try to connect
before asked explicitly with REASSOCIATE or RECONNECT.

Fix this by making ENABLE_NETWORK setting of reassociate = 1 and
starting of scans for connection conditional on wpa_s->disconnected ==
0. This will make ENABLE_NETWORK trigger a connection only if
wpa_supplicant is already in a state where it would try to connect if
there are any enabled networks.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>