build-and-provide-package: set ADDITIONAL_BUILDRESULTS also in custom pbuilderrc
build-and-provide-package: set ADDITIONAL_BUILDRESULTS also in custom pbuilderrc

If LINTIAN=yes is set, to run lintian from inside the build environment,
we need to make sure the ADDITIONAL_BUILDRESULTS reaches pbuilder.
Ad least when using a custom pbuilderrc (like
PBUILDER_CONFIG=/etc/jenkins/pbuilderrc inside /etc/jenkins/debian_glue)
then we need to make sure it's also part of the runtime pbuilderrc.

Development sponsored by Sipwise GmbH, recorded as
TT#15150 in customers' ticket system.

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