A cron job bug (T239808) meant that we didn't collect LinkSearch totals for a couple of months. These months now show zero links when they should really not have a data point at all, for clarity.

If a month actually has recorded data at zero, that should still show as zero on the graph.

Acceptance criteria

• On the total links graph, if no data is found for a month, there should be no data point instead of one at zero