added configure glibc to glibc page

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@2262 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/glibc.xml

@@ -8,6 +8,7 @@ Estimated required disk space:  &glibc-compsize;</screen>
 &aa-glibc-shortdesc;
 &aa-glibc-dep;
 &c6-glibc-inst;
+&c6-cf-glibc;
 
 </sect1>