Possible issue with how triggers are started

Original reporter pascalw

I noticed that when creating projects with this plugin the Github plugin doesn't create webhooks like it normally does on regular projects.

I've debugged this issue a bit and noticed that on multi branch projects the Github trigger `start` method is always called with `newInstance = false` whereas on regular projects the it's called with newInstance = true. Looking at the code I think this could possibly originate from https://github.com/mjdetullio/multi-branch-project-plugin/blob/54d7e5ebde04a13469d96b883cb81ce11351164f/src/main/java/com/github/mjdetullio/jenkins/plugins/multibranch/FreeStyleMultiBranchProject.java#L964 where the start method is indeed called with newInstance=false.

What I'm confused about however is whether the triggers should be started from the parent project at all or if they should be started on each child project. In any case the behavior of starting triggers seems to be different in multi branch projects vs regular projects. mjdetullio can you help me understand this issue? If this is an actual issue I would like to fix it but I first want to make sure I fully understand the issue.