fix profile icon format

migrations/profileImageFormat.js

@@ -0,0 +1,11 @@
+db.objects.find({type: "Group"}).forEach(function(d) {
+  if(typeof d.icon !== 'string') {
+    return;
+  }
+  d.icon = {
+    type: 'Image',
+    mediaType: 'image/jpeg',
+    url: d.icon
+  };
+  db.objects.save(d);
+});

pub/actor.js

@@ -39,7 +39,11 @@ function createLocalActor (name, type) {
       preferredUsername: name,
       name: `${name} group`,
       summary: `I'm a group about ${name}. Follow me to get all the group posts. Tag me to share with the group. Create other groups by searching for or tagging @yourGroupName@${config.DOMAIN}`,
-      icon: `https://${config.DOMAIN}/f/guppe.png`,
+      icon: {
+        type: 'Image',
+        mediaType: 'image/jpeg',
+        url: `https://${config.DOMAIN}/f/guppe.png`
+      },
       publicKey: {
         id: `${actorBase}#main-key`,
         owner: `${actorBase}`,