fix sphinx error
fix sphinx error

pllim/astropy,mhvk/astropy,dhomeier/astropy,MSeifert04/astropy,DougBurke/astropy,lpsinger/astropy,funbaker/astropy,MSeifert04/astropy,StuartLittlefair/astropy,stargaser/astropy,stargaser/astropy,astropy/astropy,StuartLittlefair/astropy,saimn/astropy,AustereCuriosity/astropy,larrybradley/astropy,AustereCuriosity/astropy,astropy/astropy,bsipocz/astropy,MSeifert04/astropy,bsipocz/astropy,pllim/astropy,kelle/astropy,astropy/astropy,lpsinger/astropy,dhomeier/astropy,bsipocz/astropy,saimn/astropy,aleksandr-bakanov/astropy,DougBurke/astropy,pllim/astropy,astropy/astropy,kelle/astropy,larrybradley/astropy,saimn/astropy,lpsinger/astropy,larrybradley/astropy,funbaker/astropy,pllim/astropy,stargaser/astropy,AustereCuriosity/astropy,larrybradley/astropy,kelle/astropy,StuartLittlefair/astropy,DougBurke/astropy,mhvk/astropy,bsipocz/astropy,larrybradley/astropy,kelle/astropy,DougBurke/astropy,dhomeier/astropy,StuartLittlefair/astropy,dhomeier/astropy,mhvk/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,saimn/astropy,mhvk/astropy,stargaser/astropy,aleksandr-bakanov/astropy,MSeifert04/astropy,saimn/astropy,funbaker/astropy,astropy/astropy,mhvk/astropy,funbaker/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,kelle/astropy,lpsinger/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,dhomeier/astropy,pllim/astropy