[wwwdocs] Simplify contribute.html a bit

[Gerald Pfeifer]

Looking at this page in some other context I noticed we became a bit
long, and I believe unnecessary so.  The two bits I am removing date
back to 2001 and 2005 (at least), respectively.  If I am wrong, and
we'll start seeing patches against release branches instead of HEAD
I'll restore the second snippet.

Gerald

Index: contribute.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/contribute.html,v
retrieving revision 1.73
diff -u -3 -p -r1.73 contribute.html
--- contribute.html	4 Aug 2009 05:37:10 -0000	1.73
+++ contribute.html	27 Jun 2010 23:23:53 -0000
@@ -232,10 +232,6 @@ and generate patches using the "<co
 "<code>-cp</code>" options.
 See <a href="http://gcc.gnu.org/wiki/SvnSetup">SVN setup instructions</a>
 for more details.
-If your version of diff does not support these options, then get the 
-latest version of GNU diff.  Patches against current development (SVN trunk) 
-are preferred to patches against releases, unless your patch is intended
-as a candidate for the release branch.
 </dd>
 
 </dl>