simplify indentation shortener via regexp, re #2470

tests/_support/Helper/Jsonapi.php

@@ -206,9 +206,7 @@ class Jsonapi extends \Codeception\Module
         $json = json_encode($jsonBody, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
 
         // This converts the default indentation of 4 spaces to 2 spaces
-        $json = preg_replace_callback('/^( +)(?=\S)/m', function ($match) {
-            return str_pad('', strlen($match[1]) / 2, ' ');
-        }, $json);
+        $json = preg_replace('/^( +)\1/m', '$1', $json);
 
         $dirname = codecept_output_dir() . 'json-for-slate/';
         if (!file_exists($dirname)) {