Queries in update 6103 fail on mysql

To reproduce:

1. Install Journal 6.x-1.2.
2. Work with it for a while and make some Journal entries.
3. Remove the journal module and replace it with the 6.x-1.x-dev version.
4. Run update.php as user 1
5. See the following:

The following queries were executed
journal module
Update #6102

    * CREATE TABLE {journal_patch} ( `pid` INT unsigned NOT NULL auto_increment, `uid` INT unsigned NOT NULL DEFAULT 0, `module` TEXT NOT NULL, `description` LONGTEXT NOT NULL, `url` VARCHAR(255) NOT NULL DEFAULT '', `status` VARCHAR(255) NOT NULL DEFAULT '', `timestamp` INT NOT NULL DEFAULT 0, PRIMARY KEY (pid) ) /*!40100 DEFAULT CHARACTER SET UTF8 */

Update #6103

    * Failed: ALTER TABLE {journal} DROP PRIMARY KEY
    * Failed: ALTER TABLE {journal} CHANGE jid `jid` INT unsigned NOT NULL auto_increment, ADD PRIMARY KEY (jid)