Update lib/php/test/Unit/Lib/StringFunc/CoreTest.php

Co-authored-by: Pavel Kvach <pavel.kvach@gmail.com>
diff --git a/lib/php/test/Unit/Lib/StringFunc/CoreTest.php b/lib/php/test/Unit/Lib/StringFunc/CoreTest.php
index 73ebbfd..b2eaac2 100644
--- a/lib/php/test/Unit/Lib/StringFunc/CoreTest.php
+++ b/lib/php/test/Unit/Lib/StringFunc/CoreTest.php
@@ -20,7 +20,7 @@
  *
  */
 
-namespace Unit\Lib\StringFunc;
+namespace Test\Thrift\Unit\Lib\StringFunc;
 
 use PHPUnit\Framework\TestCase;
 use Thrift\StringFunc\Core;