expire invite on existing user

app/controllers/api/v1.controller.js

@@ -101,6 +101,8 @@ class v1 {
                 project.shared_user_ids.push(req.session.auth.uuid)
                 await project.save()
             }
+            invite.used = true
+            await invite.save()
             return res.redirect('/dash/v1')
         }
         else {