allow capturing of errors with values of empty strings
allow capturing of errors with values of empty strings

DramaFever/raven-go,getsentry/raven-go,mpuncel/raven-go,getsentry/raven-go,DramaFever/raven-go,bigdrum/raven-go,bigdrum/raven-go,Invacio/raven-go,mpuncel/raven-go