This reverts commit 8bffa4d520edd1559d25c0fc7e2635f60e504d56.
8bffa4d520edd1559d25c0fc7e2635f60e504d56 introduced a bug where new jobs
without a `disabled` value configured in their source would fail to be
created on Jenkins.
Reverting 8bffa4d520edd1559d25c0fc7e2635f60e504d56 for now while the bug
is addressed and sufficient test cases created to catch such a
regression.
Change-Id: Ia8adc1f8394b6a745e8bbc7038c85958c56fd11b