Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  23bba6e81d49b01a2499e3136288c60bc3cdbdc5

Don't autosubscribe to new topics

Subscribe to board no longer means auto-subscribe to new topics.
We've discussed that this created too many notifications, so
kill it.

This is partly a revert of I5ed61349c9c1

Change-Id: I2c0e07c3f96eda426dd0b8d181f2322b0241e348