Release candidates haven't been in a 'beta' subdir in a long time, so let's
replace the dead link with an explanation instead.
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
<p>
When a new release is coming, release candidates (betas) may be found
-<a href="ftp://ftp.freedesktop.org/pub/mesa/beta/">here</a>.
+in the same directory, and are recognisable by the
+<tt>mesa-Y.N.P-<b>rc</b>X.tar.gz</tt> filename.
</p>