Fix exception case in get_config
Fix exception case in get_config

StuartLittlefair/astropy,pllim/astropy,astropy/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,pllim/astropy,larrybradley/astropy,larrybradley/astropy,StuartLittlefair/astropy,astropy/astropy,saimn/astropy,lpsinger/astropy,lpsinger/astropy,astropy/astropy,astropy/astropy,aleksandr-bakanov/astropy,mhvk/astropy,mhvk/astropy,saimn/astropy,astropy/astropy,lpsinger/astropy,mhvk/astropy,pllim/astropy,lpsinger/astropy,mhvk/astropy,saimn/astropy,saimn/astropy,larrybradley/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,saimn/astropy,larrybradley/astropy,StuartLittlefair/astropy,pllim/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,mhvk/astropy,pllim/astropy