- minor optimisation in rrd:add_with/4 (do not check for future slot if already known that the value is in the current slot)
- minor optimisation in rrd:add_with/4 (do not check for future slot if already known that the value is in the current slot)

l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror