Do not log port when config is invalid (#5865)
Do not log port when config is invalid (#5865)

When configuration is invalid config might be `null` so it
will cause NPE when we try to log it. This patch removes logging
of port that causes NPE.

Fixes: MARATHON-7998
mesosphere/marathon,janisz/marathon,mesosphere/marathon,meln1k/marathon,gsantovena/marathon,guenter/marathon,meln1k/marathon,janisz/marathon,meln1k/marathon,janisz/marathon,meln1k/marathon,gsantovena/marathon,guenter/marathon,guenter/marathon,janisz/marathon,mesosphere/marathon,guenter/marathon,janisz/marathon,gsantovena/marathon,gsantovena/marathon,gsantovena/marathon,guenter/marathon,mesosphere/marathon,mesosphere/marathon,meln1k/marathon