Improve wekan performance (checklist collection scan)

models/boards.js

@@ -414,9 +414,7 @@ if (Meteor.isServer) {
       _id: 1,
       'members.userId': 1,
     }, { unique: true });
-    Boards._collection._ensureIndex({
-      'members.userId': 1,
-    }, { unique: true });
+    Boards._collection._ensureIndex({'members.userId': 1});
   });
 
   // Genesis: the first activity of the newly created board

models/checklists.js

@@ -133,6 +133,10 @@ Checklists.mutations({
 });
 
 if (Meteor.isServer) {
+  Meteor.startup(() => {
+    Checklists._collection._ensureIndex({ cardId: 1, createdAt: 1 });
+  });
+
   Checklists.after.insert((userId, doc) => {
     Activities.insert({
       userId,