THRIFT-4794: finish php json cross test
diff --git a/test/php/test_php.ini b/test/php/test_php.ini
index 3f9bb21..aeb67cb 100644
--- a/test/php/test_php.ini
+++ b/test/php/test_php.ini
@@ -1,2 +1,3 @@
 extension=thrift_protocol.so
+extension=json.so
 extension=sockets.so