Update Glance configuration sample files for database options

Sample configuration files are out of date with respect to database
options. This change makes the options up-to-date.

Closes-bug: #1285617
Change-Id: I2694425a0b1610f37e77f1bc81aebed850a16348
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>