[BUGFIX] dbal: Always initialize the DBMS specifics

[BUGFIX] dbal: Always initialize the DBMS specifics

Make default DBMS specifics available when no DBAL handler has
been configured to fix errors in the install tool.

Resolves: #67380
Releases: master
Change-Id: I8140fbe570628a5747e21a6e07920b8fbdc820b1
Reviewed-on: http://review.typo3.org/40135
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>