fix build warning
fix build warning

jcristovao/persistent,jcristovao/persistent,gbwey/persistent,mkscrg/persistent,greydot/persistent,junjihashimoto/persistent,meteficha/persistent,paul-rouse/persistent,greydot/persistent,creichert/persistent,jcristovao/persistent,naushadh/persistent,andrewthad/persistent,greydot/persistent,mitchellwrosen/persistent,nakaji-dayo/persistent,jasonzoladz/persistent,mkscrg/persistent,meteficha/persistent,rdnetto/persistent,gbwey/persistent,andrewthad/persistent,mkscrg/persistent,gbwey/persistent,jasonzoladz/persistent,gbwey/persistentold,plow-technologies/persistent,pseudonom/persistent,jasonzoladz/persistent,gbwey/persistentold,pseudonom/persistent,andrewthad/persistent,nakaji-dayo/persistent,superduper/persistent,mitchellwrosen/persistent,junjihashimoto/persistent,rdnetto/persistent,superduper/persistent,mitchellwrosen/persistent,bitemyapp/persistent,meteficha/persistent,erikd/persistent,psibi/persistent,nakaji-dayo/persistent,superduper/persistent,yesodweb/persistent