Fix a sed in Chapter 6 gettext.

git-svn-id: svn://svn.linuxfromscratch.org/LFS/trunk/BOOK@11405 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/gettext.xml

@@ -65,7 +65,7 @@ sed -i 's/test-lock..EXEEXT.//' gettext-tools/gnulib-tests/Makefile.in</userinpu
    to be in metainfo.{its,loc},  When updating, check BLFS gnome-screenshot. -->
    <para>现在修复一个配置文件：</para>
 
-<screen><userinput remap="pre">sed -e '/AppData/N;N;p;s/\.appdata\./.metainfo./' \
+<screen><userinput remap="pre">sed -e '/AppData/{N;N;p;s/\.appdata\./.metainfo./}' \
     -i gettext-tools/its/appdata.loc</userinput></screen>
 
     <para>准备编译 Gettext：</para>