Edit common - moderators cannot edit common

[watchtower314]

Steps to reproduce:

1. As a moderator, go to Edit Common
2. Edit some field

Expected result:
The common is edited in the database

Actual result:
The common is only updated in the store, but the database is not updated because the user is not the founder of the common

[watchtower314]

frontend pr: daostack/common#1070
backend pr: #404 (well, I guess PR not found 🤣)

[yanivi71]

Tested on Staging iOS version 1.9.7 (6591)
Tested on Staging Android version 1.9.7 (6591-240)
Found OK
moderator can edit common.

[yanivi71]

tested on production
Found OK
moderator can edit common.