PLATFORM-317: Phalanx should ignore Wikia's border-http-s4/5 IPs

@michalroszka / @Wikia/platform-team 

Log cases when we're missing Fastly request header with "original" client IP.
@nmonterroso, just an idea: add ``getLogger`` method to WikiaObject so we can avoid ``use`` statements or long calls to ``Wikia\Logger\WikiaLogger::getInstance()``. What do you think?