v1.9.1 - Create zone: Zone name input keeps focus

Focus fix for the Create zone form. No schema change, no migration. Pull the new
tag and recreate the container.

Fixed

• Zone name input lost focus after the first character on Create zone. The shared
  form field rendered its control as a lone element until a sibling appeared next to it
  (the "Stored as" preview that shows on the first keystroke), and React remounted the
  input on that change of shape. The field now renders its children in one stable shape,
  so every field whose control is followed by a conditional note keeps focus.
  (#161)