Instead of going through the configuration exchange, reject invalid
legacy configurator parameters explicitly. Previously, configuring
legacy (psk/sae) parameters without psk/pass resulted in a config object
that used a zero length passphrase. With this change, that config object
is not sent and instead, either the initialization attempts is rejected
or the incoming initialization attempt is ignored.
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>