Switch from Priority extra to optional
Switch from Priority extra to optional

The Debian archive does not have this priority anymore.

mika/jenkins-debian-glue,hashar/jenkins-debian-glue,hashar/jenkins-debian-glue,kartikm/jenkins-debian-glue,linuxmaniac/jenkins-debian-glue,kartikm/jenkins-debian-glue,linuxmaniac/jenkins-debian-glue,mika/jenkins-debian-glue