Active multi-project issues on restricted trackers

[skalimer0]

Issue #29

[nanego]

Hello
Thank you for submitting this pull request. It's a straightforward way to introduce the feature.

However, it would add another configuration step after the installation of the plugin, which would require documentation.

Moreover, for current users, if someone updates the plugin in production, the feature will cease to function if they neglect to select every tracker in the plugin configuration.
They would also need to update these settings each time they add a tracker in the application.

Due to these considerations, I won't merge the proposed code as is. However, we can collaborate on a new version of this patch, which would also include some tests.

[skalimer0]

Thanks you for your return.
I change to support empty tracker selection to enable for all.
It's better, for sure.