Disable header in Catch Kathmandu

I hope you can help me with an little problem. Catch Kathmandy has the possibility to place a small logo in the header. However, I prefer an header/image with an logo in it. Now I have an white space at the top of the website (see: http://www.verjaardagswinkel.nl/ ). Is there an solution to disable that whit-space? Thank you for your answer in advance.