wormsquiggle

Hi, I'm having this issue with Cura 2.7.0 when I specify a wall line count and zero infill it generates extra line segments and extra travel moves that are unnecessary. The model can be found here: https://www.thingiverse.com/thing:523972 Even if i set a wall line count of one, it still does it. Anyone know if i'm doing something wrong? I would like to print the wall with a 3 line thickness but don't want all the stringing this will produce Thanks so much for any help