Fix typo that caused crash when Cython is not installed
Fix typo that caused crash when Cython is not installed

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