Removed the demand to post trivial patches to lwip-users, things keep getting lost there.

doc/contrib.txt

@@ -46,11 +46,7 @@ features of Savannah help us not lose users' input.
 4. Do not file a bug and post a fix to it to the patch area. Either a bug report
    or a patch will be enough.
    If you correct an existing bug then attach the patch to the bug rather than creating a new entry in the patch area.
-5. Trivial patches (compiler warning, indentation and spelling fixes or anything obvious which takes a line or two)
-   can go to the lwip-users list. This is still the fastest way of interaction and the list is not so crowded
-   as to allow for loss of fixes. Putting bugs on Savannah and subsequently closing them is too much an overhead
-   for reporting a compiler warning fix.
-6. Patches should be specific to a single change or to related changes.Do not mix bugfixes with spelling and other
+5. Patches should be specific to a single change or to related changes.Do not mix bugfixes with spelling and other
    trivial fixes unless the bugfix is trivial too.Do not reorganize code and rename identifiers in the same patch you
    change behaviour if not necessary.A patch is easier to read and understand if it's to the point and short than
    if it's not to the point and long :) so the chances for it to be applied are greater.