This commit upgrades the protobuf version. Compared to the previous
v1.2.0 it generates smaller diffs in generated code. This change was
introduced in:
fffb0f7828
This commit adds a new service lnrpc/autopilot, that is to be used to
communicate with the running autopilot. Currently a RPC for getting the
status of the agent is included, as well as enabling/disabling at
runtime.