Moved icon_emoji parameter to correct position for SlackHandler

Author: Derek Clapham

DependencyInjection/MonologExtension.php

@@ -448,9 +448,9 @@ private function buildHandler(ContainerBuilder $container, $name, array $handler
                 $handler['channel'],
                 $handler['bot_name'],
                 $handler['use_attachment'],
+                $handler['icon_emoji'],
                 $handler['level'],
                 $handler['bubble'],
-                $handler['icon_emoji'],
             ));
             break;