Remove outdated MyISAM support. Engines are smart enough to determine their engine. MySQL uses InnoDB since 5.5 as default.
So for that in InnoDB, auto_increment keys have to have to: either have their own index, or at least be the primary sub-index of a compound index. (a in KEY(a,b)).
If not it throws ERROR 1075 (Incorrect table definition).

Signed-off-by: Sven Rissmann <creaworld-media@gmx.de>