TT#56376 selenium: fix crash when deleting header rule condition

controller_header.t:
- removed fill_element when checking if header rule condition was deleted,
since it isn't really necessary plus it causes problems with stale elements

Change-Id: I8e2c1ec89a0986531987b6fca07973104e18333f

t/selenium/controller_header.t

@@ -215,7 +215,6 @@ $d->find_element('//*[@id="dataConfirmOK"]')->click();
 
 diag('Check if Header Rule Condition was deleted');
 is($d->get_text('//*[@id="content"]//div[contains(@class, "alert")]'), 'Header rule condition successfully deleted',  "Correct Alert was shown");
-$d->fill_element('//*[@id="header_rule_conditions_table_filter"]//input', 'xpath', $headercondition);
 ok($d->find_element_by_css('#header_rule_conditions_table tr > td.dataTables_empty', 'css'), 'Header Rule Condition was deleted');
 
 diag('Go to Header Rule Actions');