In all places we use this function the $table argument has already
been passed through table_name() method, i.e. it contains the prefix
and is quoted. So, we should not do this again.
When a deadlock error occurs, MySQL rolls back the _entire_ ongoing
transaction. The application would have to restart the transaction from
the beginning to retry if wanted.
Now roundcube in that case simply retries the statement that raised the
deadlock error, even though everything else in the transaction was
rolled back. This breaks transaction isolation, leaves the database in a
potentially inconsistent state (from the application's data consistency
model point of view), and does not indicate to the application there was
a problem at all to it may even continue executing other potentially
remaining statements of a transaction that has already been rolled back.
-> Remove the retries from roundcube. Retries have to be initiated by
the application if desired, not only retrying the last statement but the
entire transaction from the beginning.
