local.conf: use PR service on jenkins.nas-admin.org by default

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
layers: bump master revisions a bit

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
bblayers: enable meta-acer for a500

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>