Move error handling for delete proxy backend method into callback

[bajiat]

When adding the rate limiting field, we added error handling using try catch. Since this is related to a Meteor method, error handling should happen inside the callback. Move error handling for delete proxy backend method into the Meteor method callback.

Example

// Calling a Meteor method with error handling
Meteor.call('methodName', function (error, result) {
  if (error) {
    // Do something with the error
  } else {
    // Do something if no error
  }
});

[bajiat]

@brylie Provide a link to the code in question.