Merge pull request #861 from hpoettker/PT-2377_table_sync_with_utf8_json

PT-2377 - fixed pt-table-sync for JSON utf8 strings

t/pt-table-sync/samples/pt-2377.sql

@@ -0,0 +1,14 @@
+DROP DATABASE IF EXISTS test;
+CREATE DATABASE test;
+USE test;
+
+CREATE TABLE `test_table` (
+  `id` INT AUTO_INCREMENT PRIMARY KEY,
+  `data` JSON NOT NULL
+) ENGINE=InnoDB;
+
+INSERT INTO
+  `test_table` (`data`)
+VALUES
+  ('{"name": "Müller"}'),
+  ('{"reaction": "哈哈"}');