Bug 11998: Revert "Bug 13805: (Plack) Disable syspref cache"

Bug 11998: Revert "Bug 13805: (Plack) Disable syspref cache"

This reverts commit ca00f0ddaeb76106b4aa274fd1848844ae042f58.

Bug 13805 fixes an installer bug by disabling the syspref cache.
It was not a good idea, it introduced performance issues (see bug 13805
comment 14).

Test plan:
Test plan:
0/ Create a new database and fill the database entry in the koha conf
with its name
1/ Go on the mainpage, you should be redirected to the installer
2/ Try to log in
You should not get the login form again.

Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>
Signed-off-by: Jacek Ablewicz <abl@biblos.pk.edu.pl>
Test plan not followed by me for this patch, due to lack of working
plack setup, but I don't expect it to cause any problems, and performace
gain for plack will be tremendous

Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com