fixed preview render crash when pages were removed
fixed preview render crash when pages were removed

tonyolag/gummi-vim,tonyolag/gummi-vim,jmarshallnz/gummi,jmarshallnz/gummi,jmarshallnz/gummi,tonyolag/gummi-vim,tonyolag/gummi-vim,jmarshallnz/gummi