api/swagger: update /containers/{id}/wait "condition" parameter to match code
api/swagger: update /containers/{id}/wait "condition" parameter to match code

This patch updates the swagger, and:

- adds an enum definition to document valid values (instead of describing them)
- updates the description to mention both "omitted" and "empty" values (although
  the former is already implicitly covered by the field being "optional" and
  having a default value).

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

jimjag/docker,cpuguy83/docker,thaJeztah/docker,jimjag/docker,moul/docker,thaJeztah/docker,thaJeztah/docker,nawawi/docker,bearstech/moby,nawawi/docker,konstruktoid/docker-upstream,Mokolea/docker,trebonian/docker,bearstech/moby,nawawi/docker,Mokolea/docker,bearstech/moby,trebonian/docker,vdemeester/docker,gnailuy/docker,konstruktoid/docker-upstream,trebonian/docker,mahak/docker,mahak/docker,bearstech/moby,moby/moby,cpuguy83/docker,nawawi/docker,gnailuy/docker,nalind/docker,nalind/docker,mahak/docker,moby/moby,flavio/docker,moul/docker,Mokolea/docker,moby/moby,vdemeester/docker,konstruktoid/docker-upstream,trebonian/docker,Mokolea/docker,moul/docker,jimjag/docker,moby/moby,mahak/docker,vdemeester/docker,jimjag/docker,moul/docker,flavio/docker,Ramzec/docker,Ramzec/docker,cpuguy83/docker,Ramzec/docker,gnailuy/docker,Ramzec/docker,nalind/docker,cpuguy83/docker,konstruktoid/docker-upstream,thaJeztah/docker,gnailuy/docker,flavio/docker,nalind/docker,flavio/docker