Do not allow ap_scan=2 scan processing to stop AP mode operation

Do not allow ap_scan=2 scan processing to stop AP mode operation

wpa_supplicant_assoc_try() would result in the currently operating AP to
get stopped if wpa_supplicant_scan() ends up getting triggered without
MANUAL_SCAN_REQ while operating an AP. With ap_scan=2, this could
resulted in unintentional stopping of AP mode operations, so check
explicitly for that case and skip the wpa_supplicant_assoc_try() call if
needed to avoid this.

Signed-off-by: Jouni Malinen <j@w1.fi>