Fix to observing example for stable numpy, completing #4657.
Fix to observing example for stable numpy, completing #4657.

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