Remove unused or incognito mwe-upwiz-campaigns-editing

Nobody knows anything about him, he didn't leave us a note,
he doesn't appear to be used anywhere, he bored us.
(I asked Romaine and grep once again.)

<https://translatewiki.net/wiki/Thread:Support/Mwe-upwiz-campaigns-editing>

Change-Id: Ibc53bad9c22b681aceaa419ea281e63ff658d055
Merge "Remove unused or incognito mwe-upwiz-campaigns-editing"