add missing validation for TextareaRows

fix warning in FormDisplay while importing settings

.gsoc/todo.txt

@@ -2,7 +2,4 @@ restore cache'ing in phpmyadmin.css.php
 make CSS for darkblue_orange
 check input escaping, $cfg is no longer safe to use
 
-preference:
-- synchronize language, theme ThemeDefault
-
-allow to import ThemeDefault
+local storage - autoload?

libraries/config.values.php

@@ -130,5 +130,6 @@ $cfg_db['_validators'] = array(
     'Servers/1/port' => 'validate_port_number',
     'Servers/1/hide_db' => 'validate_regex',
     'TextareaCols' => 'validate_positive_number',
+    'TextareaRows' => 'validate_positive_number',
     'TrustedProxies' => 'validate_trusted_proxies');
 ?>

libraries/config/FormDisplay.class.php

@@ -528,7 +528,9 @@ class FormDisplay
                         break;
                     case 'array':
                         // eliminate empty values and ensure we have an array
-                        $post_values = explode("\n", $_POST[$key]);
+                        $post_values = is_array($_POST[$key])
+                            ? $_POST[$key]
+                            : explode("\n", $_POST[$key]);
                         $_POST[$key] = array();
                         foreach ($post_values as $v) {
                             $v = trim($v);