According to Red Alert Politics, this image was posted on the Rote Antifa Facebook page:
They say the caption translated as "Prefer sexually active fugitive as German racists" (sic). They acknowledge that the original photo was photoshopped before being posted, but ascribe the views of the (altered) sign to the entire group.
Was the photo saying "Will Trade Racists for Rapists" posted on the Rote Antifa site?