Support table creation w/o primary key

[weotch]

This disables the sql_require_primary_key setting (which is enabled by default on DigitalOcean Managed Databases) in advance of table creation so that the createTable for the message table doesn't have a fatal error like this:

General error: 3750 Unable to create or change a table without a primary key, when the system variable 'sql_require_primary_key' is set. Add a primary key to the table or unset this variable to avoid this message. Note that tables without a primary key can cause performance problems in row-based replication, so please consult your DBA before changing this setting.
The SQL being executed was: CREATE TABLE `message` (
  `id` int(11) NOT NULL,
  `dateCreated` datetime(0) NOT NULL,
  `dateUpdated` datetime(0) NOT NULL,
  `uid` char(36) NOT NULL DEFAULT '0',
  `language` varchar(16) NOT NULL,
  `translation` text
) CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB

This is similar to the Laravel workaround described here: https://github.com/laravel/framework/issues/33238#issuecomment-648071415

[smcyr]

Looks good to me, thanks!