docs: make xconfig now uses libqt4

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

docs/buildroot.html

@@ -160,13 +160,13 @@
  $ make gconfig
 </pre>
 
-    <p>to run the Qt3 or GTK-based configurators.</p>
+    <p>to run the Qt or GTK-based configurators.</p>
 
     <p>All of these "make" commands will need to build a configuration
     utility, so you may need to install "development" packages for relevant
     libraries used by the configuration utilities. On Debian-like systems,
     the <code>libncurses5-dev</code> package is required to use the <i>
-    menuconfig</i> interface, <code>libqt3-mt-dev</code> is required to use
+    menuconfig</i> interface, <code>libqt4-dev</code> is required to use
     the <i>xconfig</i> interface, and <code>libglib2.0-dev, libgtk2.0-dev
     and libglade2-dev</code> are needed to use the <i>gconfig</i> interface.</p>