Look at correct constraint field

Old:

  $ curmeteor add iron:router@9.9.9
  Got error during resolve; trying refresh { [Error: conflict: constraints on iron:router cannot be satisfied.
  Constraints come from:
    <top level>] constraintSolverError: true }
  Could not satisfy all the specified constraints:
  Error: conflict: constraints on iron:router cannot be satisfied.
  Constraints come from:
    <top level>

New:

  $ curmeteor add iron:router@9.9.9
  iron:router@9.9.9: no such version