Give project actors signing keys, just like user actors, needed for forwarding

Since project actors are the ones sending inbox forwards, they need to announce
keys and allow their HTTP Signatures to be verified.

src/Vervis/Handler/Project.hs

@@ -140,7 +140,10 @@ getProjectR shar proj = selectRep $ do
                 Just $ fromMaybe (prj2text proj) $ projectName project
             , actorSummary    = projectDesc project
             , actorInbox      = route2local $ ProjectInboxR shar proj
-            , actorPublicKeys = []
+            , actorPublicKeys =
+                [ Left $ route2local ActorKey1R
+                , Left $ route2local ActorKey2R
+                ]
             }
 
 putProjectR :: ShrIdent -> PrjIdent -> Handler Html