Revert option to filter by last N days
Revert option to filter by last N days

The Gerrit 'age' filter returns patches that were last *updated*
in the last 'age' time, not patches *created* in that time.
That means that the graph that is produced is misleading, the
time to merge will always seem like it starts high then goes
low.

assafmuller/gerrit_time_to_merge