Backport static:: to classname:: for PHP 5.3 compatibility

src/Silex/Provider/MonologServiceProvider.php

@@ -36,7 +36,7 @@ class MonologServiceProvider implements ServiceProviderInterface
 
         if ($bridge = class_exists('Symfony\Bridge\Monolog\Logger')) {
             $app['monolog.handler.debug'] = function () use ($app) {
-                $level = static::translateLevel($app['monolog.level']);
+                $level = MonologServiceProvider::translateLevel($app['monolog.level']);
                 return new DebugHandler($level);
             };
         }
@@ -56,7 +56,7 @@ class MonologServiceProvider implements ServiceProviderInterface
         });
 
         $app['monolog.handler'] = function () use ($app) {
-            $level = static::translateLevel($app['monolog.level']);
+            $level = MonologServiceProvider::translateLevel($app['monolog.level']);
             return new StreamHandler($app['monolog.logfile'], $level);
         };