use old methods and redirect in deprecated methods

lib/private/allconfig.php

@@ -106,7 +106,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $value the value that you want to store
 	 */
 	public function setUserValue($userId, $appName, $key, $value) {
-		\OCP\Config::setUserValue($userId, $appName, $key, $value);
+		\OC_Preferences::setValue($userId, $appName, $key, $value);
 	}
 
 	/**
@@ -119,7 +119,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @return string
 	 */
 	public function getUserValue($userId, $appName, $key, $default = '') {
-		return \OCP\Config::getUserValue($userId, $appName, $key, $default);
+		return \OC_Preferences::getValue($userId, $appName, $key, $default);
 	}
 
 	/**

lib/public/config.php

@@ -131,7 +131,7 @@ class Config {
 	 * not exist the default value will be returned
 	 */
 	public static function getUserValue( $user, $app, $key, $default = null ) {
-		return \OC_Preferences::getValue( $user, $app, $key, $default );
+		return \OC::$server->getConfig()->getUserValue( $user, $app, $key, $default );
 	}
 
 	/**
@@ -148,7 +148,7 @@ class Config {
 	 */
 	public static function setUserValue( $user, $app, $key, $value ) {
 		try {
-			\OC_Preferences::setValue( $user, $app, $key, $value );
+			\OC::$server->getConfig()->setUserValue( $user, $app, $key, $value );
 		} catch (\Exception $e) {
 			return false;
 		}