Drop rc_cur_time from recentchanges

Field was removed in 1.23 from sql statements, but kept to allow easier
rollback on version update from 1.22 -> 1.23, when something gets wrong
with the new version.

Bug: 40667
Follow-Up: I4a9c2fa813d1f25dfb755e564f7677a212934d7b
Change-Id: I48989aceec31019f0b6c98aaeafaf60e975244df
Merge "Drop rc_cur_time from recentchanges"