fix rvm_requiremnts_fail_or_run_action, update #1720, update #1724, f…

…ound: http://stackoverflow.com/questions/15587298/cant-install-ruby-1-9-3-via-rvm-in-os-x-lion-even-with-with-gcc-clang/15587558?noredirect=1#comment22320984_15587558

scripts/functions/build_requirements

@@ -17,7 +17,7 @@ rvm_requiremnts_fail_or_run_action()
       return 1
       ;;
     (*)
-      shift
+      shift 2
       "$@" || return $?
       ;;
   esac