matrix-ng split into multiple submodules causes some changes in keys
that might've been used for homeserver/riot configuration customization.
Migration to kube.Namespace.Contain has also caused change in Deployment
selectors (immutable fields), thus needing manual removal of these
first.
This is, as always, documented in lib/matrix-ng.libsonnet header.
Change-Id: I39a745ee27e3c55ec748818b9cf9b4e8ba1d2df5
