Drifting base layout always users 'topcomment' as the reply_container target so quickreply doesn't work on some pages

[sgsabbage]

Specifically, here: https://github.com/dreamwidth/dw-free/blob/develop/styles/drifting/layout.s2#L1207-L1208 which is incompatible with how quickreply uses the target container.

[rshatch]

Claiming

[kareila]

Fixed by #1914.