libgksu doesn't translate a "Password: " string correctly

Recently I did a translation of gksu, libgksu and libgksuui packages.
While testing the resulting translation I've found one situation when
the window asking for the password was translated only in 95%.
And exactly one string, namely "Password: " was always displayed
in original (English).
This was odd, because I was positively sure that this string
was translated correctly. However, that resulted in an unaesthetic
situation: almost all messages translated and one big "Password: "
in the center of the window...

Eventually I've found that this is due to the way how libgksuui
interacts with the login tty. So in fact this "Password: " string was
coming from the tty, and not from the libgksuui's missing translation.

I've created a small patch against libgksu/gksu-context.c file, based
on the fact that exactly the same string is already translated in the
libgksuui's .po files. It works this way:
- compares the string buffer read from the tty with the constant
 "Password: " string
- if the strings match, buffer is replaced with the translated string
- finally 'ask_pass' function is called with the resulting prompt

The patch is in the libgksu1.2-1.3.7-localized-prompt.patch file.
Please review it and if you find it useful, please apply. With this patch the
gksu combo is "complete" - so all messages displayed on the screen
are properly translated.