chapter06/file: Remove extra space from the end of one of the configure lines, which causes configure to fail to run.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@12127 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/file.xml

@@ -51,7 +51,7 @@
 
 <screen><userinput remap="pre">mkdir build
 pushd build
-  ../configure --disable-bzlib      \ 
+  ../configure --disable-bzlib      \
                --disable-libseccomp \
                --disable-xzlib      \
                --disable-zlib