Fix biweight scale and midvariance when mad=0 and axis is input
Fix biweight scale and midvariance when mad=0 and axis is input

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