config: can't assume key_control to be enabled if there is no DMI information

Because otherwise, there won't be a way to actually disable it if it needs to
be disabled, since if it fails to start, the daemon aborts.

Signed-off-by: Mathieu Trudel-Lapierre <mathieu.trudel-lapierre@canonical.com>
Merge pull request #6 from cyphermox/master

config: can't assume key_control to be enabled if there is no DMI inform...