Tidb: select @@version and select version() return different VERSION

[forestkeeper]

````
mysql> select @@version;
+-----------+
| @@version |
+-----------+
| 5.6.25 |
+-----------+
1 row in set (0.00 sec)

mysql> select Version();
+----------------+
| Version() |
+----------------+
| 5.7.1-TiDB-1.0 |
+----------------+
1 row in set (0.01 sec)
````

[shenli]

@forestkeeper Thanks for your report! We will fix it.

[ngaut]

The bug has fixed. You may want to try the latest master.