No manual db setup in Debian

In Debian, there's no need to do manual configuration
of the database settings, as this is handled by debconf.
This patch removes the step for the Debian guide, and also
removes the step where Glance daemons are restarted (also
not needed in Debian).

Change-Id: I964669492277b0d13a46c8ad8009c51aa6e0c493
Closes-bug: #1310048
Merge "No manual db setup in Debian"