BUG #6066: Bad string in German translation causes segfault (user-triggerable)

The following bug has been logged online:

Bug reference:      6066
Logged by:          Christoph Berg
Email address:      cb@df7cb.de
PostgreSQL version: 9.1, 9.0, 8.4
Operating system:   any
Description:        Bad string in German translation causes segfault
(user-triggerable)
Details:

In German locale, the follow statement causes vsnprintf() to segfault when
printing the hint:

SELECT TO_DATE('30.12.2011', 'YYYYMMDD') AS datum;

Fix tested for 8.4:

$ diff -c src/backend/po/de.po.orig src/backend/po/de.po
*** src/backend/po/de.po.orig    2011-06-17 10:06:41.000000000 +0200
--- src/backend/po/de.po    2011-06-17 10:06:48.000000000 +0200
***************
*** 12318,12324 ****
  "If your source string is not fixed-width, try using the \"FM\"
modifier."
  msgstr ""
  "Wenn die Quellzeichenkette keine feste Breite hat, versuchen Sie den "
! "Modifikator »%s«."

  #: utils/adt/formatting.c:1886 utils/adt/formatting.c:1899
  #: utils/adt/formatting.c:2029
--- 12318,12324 ----
  "If your source string is not fixed-width, try using the \"FM\"
modifier."
  msgstr ""
  "Wenn die Quellzeichenkette keine feste Breite hat, versuchen Sie den "
! "Modifikator »FM«."

  #: utils/adt/formatting.c:1886 utils/adt/formatting.c:1899
  #: utils/adt/formatting.c:2029