Update Campaign on Contact Segments change If batch is lower

[kuzmany]

What type of report is this:

Q	A
Bug report?	n
Feature request?	y
Enhancement?	n

Description:

This feature request is based on #3058.

What's the problem

If we're using dynamic content we are able to add contact to segments from page visits.
But we have to wait for segments update and campaign rebuild cron.
Thats mean, we cannot fire dynamic content for new visitors, just for returning visitors.

Solution

We should add new configration option for enable onLeadListChange if segments contacts update is lower than some number.

Thats mean if segments is update with 10 contacts, every contact will update in campaigns.

mautic/app/bundles/CampaignBundle/EventListener/LeadSubscriber.php

Line 123 in afb4da4

public function onLeadListChange(ListChangeEvent $event)