Trying to connect Jenkins 2.107.1 to my gitlab install using the jenkins config page.

Using a self signed cert on gitlab.

Pulled the cert down from gitlab and inserted it in both

/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/jre/lib/security/cacerts

and 
/var/lib/jenkins/tools/hudson.model.JDK/jdk_1.8.0_121/jre/lib/security/cacerts

but still reports failure to recognise the cert 

Client error: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target