Allow disabled addons to be omitted from .config
Allow disabled addons to be omitted from .config

When running "make config" or "make menuconfig," options that are
disabled don't necessarily go into .config with values of "n." In some
versions of kconfig-frontends, like the one in this repo's Docker image,
comments get stored instead:

  # .phase3.dashboard is not set

Without this change, attempting to run "make addons" or even just
"phase3/do gen" chokes on these values, since jsonnet can't find
configuration for them. With the change, it treats addons omitted from
.config as disabled.

This should also help upgrade-proof clients that automate the creation
of .config, so upstream additions of new addons don't render old .config
files broken.

weaveworks/kubernetes-anywhere,weaveworks/weave-kubernetes-anywhere,rohitjogvmw/kubernetes-anywhere