[netcurl] NetCurl vs PHP 8.1 Update

Since PHP 8.1 has a alpha release in place, I also took a chance yesterday to make sure that the netcurl 6.1 release still works when 8.1 go live "for real". As it seems, there was just a few adjustments, that probably does not affect production environment even now. But why take any risks? Version 6.1.5 is therefore prepared to be 8.1-safe. There will be further tests on this release, before it will be entirely closed. As of this release, both github and the old bitbucket-server will have their own issue tracking. Since Atlassian is dropping all their server support 2023-2024, there's probably not good to wait with any migrations until then. Regards, Your NetCurl Developer