[-] CORE : Remove notices on ob clean

install-dev/classes/controllerHttp.php

@@ -417,7 +417,8 @@ abstract class InstallControllerHttp
 		if ($get_output)
 		{
 			$content = ob_get_contents();
-			ob_end_clean();
+			if (ob_get_level() && ob_get_length() > 0)
+				ob_end_clean();
 			return $content;
 		}
 	}

install-dev/controllers/http/smarty_compile.php

@@ -40,4 +40,5 @@ require_once(_PS_ROOT_DIR_.'/config/smarty.config.inc.php');
 $smarty->setTemplateDir($directory);
 ob_start();
 $smarty->compileAllTemplates('.tpl', false);
-ob_end_clean();
+if (ob_get_level() && ob_get_length() > 0)
+	ob_end_clean();