[Druid] conference paper access

Dear Sir/Madam, I am a presenter of DRUID 2018. I just find that my paper can be accessed publicly (https://conference.druid.dk/acc_papers/j3hkhnds0y112f4m017sb32hxd29p2.pdf). I am now planning to submit the paper to a journal and that might influence my submission. Could I request to withdraw my paper or restrict public access? Thank you very much! Regards, Yuni