docker: Fix database error during initial migration

The following error was shown during initial startup of the container
and the database was obviously not initialized because of this. I'm not
sure why it happens, but setting the database name in the config (in
addition to the name in the PDO connection string) fixes the problem.

> Database error: A Database Error Occurred
>
>    Error Number: 42000/1102
>    Incorrect database name ''
>    SHOW TABLES FROM ``
>    Filename: libraries/Migration.php
>    Line Number: 167

Signed-off-by: Florian Pritz <bluewind@xinu.at>

0 files changed, 0 insertions, 0 deletions