Revert change introduced inadvertently in libstdc++ at r11760

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@11761 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>
 
@@ -78,7 +78,7 @@ cd       build</userinput></screen>
           instead of the one in <filename>/usr/bin</filename>.</para>
         </listitem>
       </varlistentry>
-        <!--
+
       <varlistentry>
         <term><parameter>--disable-libstdcxx-threads</parameter></term>
         <listitem>
@@ -86,7 +86,7 @@ cd       build</userinput></screen>
           thread library cannot be built either.</para>
         </listitem>
       </varlistentry>
-        -->
+
       <varlistentry>
         <term><parameter>--disable-libstdcxx-pch</parameter></term>
         <listitem>