Fixed visual bug in single layer preview
Fixed visual bug in single layer preview

jrial/Repetier-Host,ethan42411/Repetier-Host,repetier/Repetier-Host,jrial/Repetier-Host,beardface/Repetier-Host-OpenSL,alex1818/Repetier-Host,josefprusa/Repetier-Host,josefprusa/Repetier-Host,repetier/Repetier-Host,repetier/Repetier-Host,alex1818/Repetier-Host,ethan42411/Repetier-Host,beardface/Repetier-Host-OpenSL,ethan42411/Repetier-Host,alex1818/Repetier-Host,jrial/Repetier-Host