jjb: infra: bifrost-cleanup-job: Do not trigger on new patchsets

jjb: infra: bifrost-cleanup-job: Do not trigger on new patchsets

Commit f6bba721fd13 ("jjb: infra: bifrost-cleanup-job: Do not trigger on
patchset creation") changed the job to not trigger on new patchsets but
this does not work as expected because it seems that the default value
for this option is 'true'. Set 'patchset-uploaded-event' to 'false' in
order to really disable that trigger.

Fixes: f6bba721fd13 ("jjb: infra: bifrost-cleanup-job: Do not trigger on patchset creation")
Change-Id: Id19474511f37ebd13d1933f5d13f185dc5c8e3c9
Signed-off-by: Markos Chandras <mchandras@suse.de>