Grid testing every permitted value on the manager pipeline surfaced two
combinations the UI allows that take the pipeline down, neither of which
the descriptions mentioned.
pipeline.ordered: true requires pipeline.workers: 1; with more workers the
pipeline fails to start with "enabling the 'pipeline.ordered' setting
requires the use of a single pipeline worker". Also correct the auto
wording: it only engages when workers is explicitly set to 1.
queue.max_bytes larger than the free space on /nsm/logstash fails queue
creation with "Unable to allocate N more bytes", rather than merely being
inadvisable.