Remove unneeded String#dup call.
Remove unneeded String#dup call.

dck/rollbar-gem,rollbar/rollbar-gem,dck/rollbar-gem,seekingalpha/rollbar-gem,seekingalpha/rollbar-gem,fabn/rollbar-gem,dck/rollbar-gem,fabn/rollbar-gem,heshamnaim/rollbar-gem,heshamnaim/rollbar-gem,rollbar/rollbar-gem,fabn/rollbar-gem,heshamnaim/rollbar-gem,seekingalpha/rollbar-gem,rollbar/rollbar-gem