add 1.21wmf12 to "good" versions, keep 1.18.6 as good, remove older 1.18

Change-Id: I97832adb38c3f228129d5c87195374cc4b8e0ab1
Merge "add 1.21wmf12 to "good" versions, keep 1.18.6 as good, remove older 1.18"