Fix header warnings from log flushing
Fix header warnings from log flushing

This resolves #1176

simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp,dnmvisser/simplesamlphp,simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp,simplesamlphp/simplesamlphp,ghalse/simplesamlphp,ghalse/simplesamlphp,dnmvisser/simplesamlphp,simplesamlphp/simplesamlphp,ghalse/simplesamlphp,ghalse/simplesamlphp