Fix minor typo in setInstallShutdownHandler doc
Fix minor typo in setInstallShutdownHandler doc

sordina/wai,utdemir/wai,utdemir/wai,frontrowed/wai,creichert/wai,yesodweb/wai,frontrowed/wai,utdemir/wai,erikd/wai,frontrowed/wai,tolysz/wai,frontrowed/wai,creichert/wai,erikd/wai,sordina/wai,tolysz/wai,erikd/wai,sordina/wai,sordina/wai,utdemir/wai,erikd/wai,tolysz/wai,yesodweb/wai,kazu-yamamoto/wai,kazu-yamamoto/wai,tolysz/wai