fix: mygroup non veniva creato i nuovi record ! mancava la dichiarazione

src/server/models/mygroup.js

@@ -8,6 +8,8 @@ const shared_consts = require('../tools/shared_nodejs');
 mongoose.Promise = global.Promise;
 mongoose.level = 'F';
 
+const { ObjectID } = require('mongodb');
+
 // Resolving error Unknown modifier: $pushAll
 mongoose.plugin(schema => {
   schema.options.usePushEach = true;