Add missing third parameter to preg_match in ChangeLogTest (#17998)

tests/framework/ChangeLogTest.php

@@ -18,7 +18,7 @@ class ChangeLogTest extends TestCase
     public function changeProvider()
     {
 
-        $lines = preg_split("~\R~", file_get_contents(__DIR__ . '/../../framework/CHANGELOG.md'), PREG_SPLIT_NO_EMPTY);
+        $lines = preg_split("~\R~", file_get_contents(__DIR__ . '/../../framework/CHANGELOG.md'), -1, PREG_SPLIT_NO_EMPTY);
 
         // Don't check last 1500 lines, they are old and often don't obey the standard.
         $lastIndex = count($lines) - 1500;