[turba] clear results?

[Paul Reilly]

> One would expect that a new search would programatically clear your
> old results when displaying the new results.

Actually, looking at the code, it appears it's maybe trying to
do this in search.php and advanced.php. The first bit of logic
near the top says:

if (!array_key_exists('turba_search_results', $_SESSION)) {
    $_SESSION['turba_search_results'] = null;
} else {
    if (Horde::getFormData('clear')) {
        $_SESSION['turba_search_results'] = null;
    }

but if I just set 'turba_search_results' to null explicitly
at the top of these files, then I get the desired effect:
When I do a search and then another search the old results are
cleared away. :)

This change seems to be working for what I want, hopefully it
won't break anything else.

Paul