jenkins: add requested plugins

As per STG-4891, let's add in a plugin requested by
the customer.

disable-github-multibranch-status:1.2

Signed-off-by: Kelley Spoon <kelley.spoon@linaro.org>
Change-Id: Ifdbeef016e2bbfe65c79bf2cb74b7d7cb635f562
1 file changed