Fix typo leading to `renderFile` not working with a callback
Fix typo leading to `renderFile` not working with a callback

[closes #1139]

Laoujin/jade,cgvarela/jade,martindale/jade,jjz/jade,Mitrend/jade,VANITAX/jade,mumaoxi/jade,harp/jade,gexiaowei/jade,angryrobot/jade,fredyteheranto/jade,webskyer/jade,cesarmarinhorj/jade,omixen/jade,nyakto/jade-async,illusionfield/jade,fredyteheranto/jade,magicdawn/jade,gexiaowei/jade,angrilove/jade,Victorgichohi/jade,Shinchy/jade,jirengu/jade,modulexcite/jade,pugjs/then-jade,coderhaoxin/jade,nyakto/jade-async,harp/jade,jirengu/jade,flintinatux/jade,pugjs/pug,rajnishyadav321/jade,jadejs/then-jade,andreytkachenko/jade,pugjs/jade,cutsin/jade,timmfin/jade,colin-h/jade,webskyer/jade,ilovezy/jade,colin-h/jade,coderhaoxin/jade,magicdawn/jade,angryrobot/jade,bogus34/jade-vfs,andreytkachenko/jade,ridixcr/jade,rajnishyadav321/jade,webmasteraxe/jade,ilovezy/jade,muthhus/jade,cesarmarinhorj/jade,illusionfield/jade,Victorgichohi/jade,bogus34/jade-vfs,pugjs/pug,jodytate/jade,Shinchy/jade,cgvarela/jade,modulexcite/jade,VANITAX/jade,pugjs/then-jade,Mitrend/jade,cutsin/jade,pugjs/jade,VeraWei/jade,VeraWei/jade,mrotaru/jade,omixen/jade,ridixcr/jade,hnag409/jade,ceremcem/jade,slang800/yade,jodytate/jade,mumaoxi/jade,jadejs/then-jade,hnag409/jade,Laoujin/jade,angrilove/jade,tranhieutt/jade,gdibble/jade,mrotaru/jade,gdibble/jade,muthhus/jade,webmasteraxe/jade,jjz/jade,tranhieutt/jade,martindale/jade