Fix `undefined method 'to_tree' for nil:NilClass` with compass sprites
Fix `undefined method 'to_tree' for nil:NilClass` with compass sprites

chriseppstein/sass,JuanitoFatas/sass,zaru/sass,schneems/sass,antonifs/sass,lmetla/sass,Nzaga/sass,srinivashappy/sass,danielfein/sass,zaru/sass,stewx/sass,danielfein/sass,tenderlove/sass,HugoRLopes/sass,nickg33/sass,OrenBochman/sass,nicklima/sass,Andrey-Pavlov/sass,srinivashappy/sass,nickg33/sass,briangonzalez/sass,ridixcr/sass,dylannnn/sass,dylannnn/sass,jaroot32/sass,stewx/sass,MetaAshley/sass,hcatlin/sass,StephanieMak/sass,PMArtz92/sass,baiyanghese/sass,jaroot32/sass,cmpereirasi/sass,Anshdesire/sass,Industrys/sass,xzyfer/sass,antonifs/sass,liquidmetal/sass,Iamronan/sass,saper/sass,cmpereirasi/sass,14113/sass,rammy7219/sass,ridixcr/sass,DanteKaris/sass,askl56/sass,StephanieMak/sass,JuanitoFatas/sass,schneems/sass,Galactix/sass,PMArtz92/sass,Ahnita/sass,tangposmarvin/sass,srawlins/sass,Ahnita/sass,Anshdesire/sass,srawlins/sass,Andrey-Pavlov/sass,OrenBochman/sass,liquidmetal/sass,Industrys/sass,xzyfer/sass,saper/sass,nicklima/sass,rammy7219/sass,modulexcite/sass,modulexcite/sass,tangposmarvin/sass,MetaAshley/sass,askl56/sass,amitsuroliya/sass,Iamronan/sass,hcatlin/sass,amitsuroliya/sass,HugoRLopes/sass,Nzaga/sass,Galactix/sass,oss-practice/sass,lmetla/sass,DanteKaris/sass