Revert "Setup/restore #mediawiki-feed"

This should be done by implementing support for a
'raw-edcho-channel' or something in grrrit-wm.

This reverts commit 993e3d89ca2b615740414cb33014c030659addaa.

Bug: 59900
Change-Id: I7ae2eb7e90fc09f33d2c71f60237b3f4c6714ad6