Now that slapos node instance no longer use --all, some software release test
revealed some problems with softwares, either missing promises or maybe
something that needs to be handled in slapos.core.
Using --all was wrong and we want to stop doing this now.
This commit is a workaround to keep the test passing, we should not have to
use waitForInstance more than once like this. Something when running slapos
node instance should detect that instance is not ready on the first run.