prevent CREATE DATABASE mysql;

[jycor]

Despite showing that mysql database exists, dolt still allows users to create one.

tmp2/main> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| tmp2               |
+--------------------+
3 rows in set (0.00 sec)

tmp2/main> create database mysql;
Query OK, 1 row affected (0.02 sec)
tmp2/main> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| mysql              |
| tmp2               |
+--------------------+
4 rows in set (0.00 sec)