Make lastUpdate more robust

Currently, lastUpdate is a parameter of Client which is not fully correct as this makes an multi runner to be registered to multiple projects on the same instance to fight with token between subsequent connections which is not very cool.

The lastUpdate should always be an parameter of RunnerConfig.

changed milestone to %v9.0

added high priority label

added ~661544 label

@tmaczukin @bkc To make you aware :)

changed milestone to %Backlog