Gitlab Jenkins Plugin

Summary

Gitlab can't test settings of Jenkins CI Plugin (on this host) (the not deprecated version)

Steps to reproduce

Activate Jenkins CI Plugin and fill in all neccessary fields and click "Test Settings"

Expected behavior

If the test was successfull or not

Relevant logs and/or screenshots## Summary

We tried to send a request to the provided URL but an error occurred: undefined method `post' for #JenkinsService:0x00000006faa0e0