format: fix logging of a boolean property

The journal callback keeps silence if the property is boolean.
It happens due the mistype in the format definition.

This commit fixes the mistype in the format definition.

Signed-off-by: Alexander Filippov <a.filippov@yadro.com>
Change-Id: Ibc0fc6d0c275d4f8d6f592794813256d529e0ccd
1 file changed