dropped obsolete --with-system-gettext configure option

Change-Id: Ia46cb802d40bb1ba199cf937f332c4b343bc22e9
Reviewed-on: https://gerrit.libreoffice.org/1060Reviewed-by: Tor Lillqvist <tml@iki.fi>
Tested-by: Tor Lillqvist <tml@iki.fi>

README.cross

@@ -158,7 +158,6 @@ CXX_FOR_BUILD=ccache g++
 --with-system-curl
 --with-system-db
 --with-system-expat
---with-system-gettext
 --with-system-hunspell
 --with-system-icu
 --with-system-libpng

configure.ac

@@ -1683,11 +1683,6 @@ AC_ARG_WITH(system-mozilla-headers,
     [with_system_mozilla_headers="$with_system_headers"]
 )
 
-AC_ARG_WITH(system-gettext,
-    AS_HELP_STRING([--with-system-gettext],
-        [Use gettext runtime library already on system.]),,
-    [with_system_gettext="$with_system_libs"])
-
 AC_ARG_WITH(system-libpng,
     AS_HELP_STRING([--with-system-libpng],
         [Use libpng already on system.]),,

distro-configs/LibreOfficeMinGW.conf

@@ -7,7 +7,6 @@
 --with-system-curl
 --with-system-db
 --with-system-expat
---with-system-gettext
 --with-system-graphite
 --with-system-hunspell
 --with-system-icu