Use plural for index columns

adminer/indexes.inc.php

@@ -106,7 +106,7 @@ $show_options = ($_POST ? $_POST["options"] : get_setting("index_options"));
 <thead><tr>
 <th id="label-type"><?php echo lang('Index Type'); ?>
 <th><input type="submit" class="wayoff"><?php
-echo lang('Column') . ($lengths ? "<span class='idxopts" . ($show_options ? "" : " hidden") . "'> (" . lang('length') . ")</span>" : "");
+echo lang('Columns') . ($lengths ? "<span class='idxopts" . ($show_options ? "" : " hidden") . "'> (" . lang('length') . ")</span>" : "");
 if ($lengths || support("descidx")) {
 	echo checkbox("options", 1, $show_options, lang('Options'), "indexOptionsShow(this.checked)", "jsonly") . "\n";
 }

adminer/lang/cs.inc.php

@@ -45,6 +45,7 @@ Lang::$translations = array(
 	'User has been created.' => 'Uživatel byl vytvořen.',
 	'Hashed' => 'Zahašované',
 	'Column' => 'Sloupec',
+	'Columns' => 'Sloupce',
 	'Routine' => 'Procedura',
 	'Grant' => 'Povolit',
 	'Revoke' => 'Zakázat',

adminer/lang/xx.inc.php

@@ -46,6 +46,7 @@ Lang::$translations = array(
 	'User has been created.' => 'Xx.',
 	'Hashed' => 'Xx',
 	'Column' => 'Xx',
+	'Columns' => 'Xx',
 	'Routine' => 'Xx',
 	'Grant' => 'Xx',
 	'Revoke' => 'Xx',