Relicense under GPLv3.

Affero has questionable legal enforceability and its concrete
requirements and reach are unclear. For example, it is unclear
whether a public service that calls a public AGPL service must be
AGPL. One might say no, but then would a public service calling an
internally hosted version of that same public AGPL service be AGPL?
If the answer is no, then AGPL is not enforceable.

More importantly, this lack of clarity and other issues around
Affero make it a poor choice of license, making lawyers nervous and
developers shy away from it.