Remove an obsolete option in libstdc++

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@11770 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter05/libstdc++.xml

@@ -63,8 +63,8 @@ cd       build</userinput></screen>
     --host=$LFS_TGT                 \
     --prefix=/tools                 \
     --disable-multilib              \
-    --disable-nls                   \
-    --disable-libstdcxx-threads     \
+    --disable-nls                   \<!--
+    - -disable-libstdcxx-threads     \-->
     --disable-libstdcxx-pch         \
     --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/&gcc-version;</userinput></screen>
 
@@ -78,15 +78,15 @@ cd       build</userinput></screen>
           instead of the one in <filename>/usr/bin</filename>.</para>
         </listitem>
       </varlistentry>
-
+        <!--
       <varlistentry>
-        <term><parameter>--disable-libstdcxx-threads</parameter></term>
+        <term><parameter>- -disable-libstdcxx-threads</parameter></term>
         <listitem>
           <para>Since gcc-pass1 is built without thread support, the C++
           thread library cannot be built either.</para>
         </listitem>
       </varlistentry>
-
+        -->
       <varlistentry>
         <term><parameter>--disable-libstdcxx-pch</parameter></term>
         <listitem>