[libstdc++ PATCH] money_get::do_get subscripts empty string

[Benjamin Kosnik]

>The problem shows up when running 22_locale/money_get/get/char/7.cc. 
>Specifically, the money_get<char,InIt>::get call at line 62 (test 
>string is "Golgafrincham") results in an empty __temp_units string at 
>the loop in question.

Thanks. This is fine.

-benjamin