Updated tags are not taken into account for busy ssh execution environments

Current situation

If a pool definition is modified to change tags on a busy channel, the newly defined tags are ignored.

For example, if the pools were:

pools:
  dynamic-dummy:
  - host: dummy.example.com
    username: foo
    password: secret
    tags: [ssh, linux, yada]
  another-pool:
  - host: yada.example.com
    username: bar
    password: never mind
    tags: [windows, abc_def]

If the dummy.example.com execution environment is busy and the pools are updated as follows:

pools:
  dynamic-dummy:
  - host: dummy.example.com
    username: foo
    password: secret
    tags: [ssh, linux, yada, yidi]
  another-pool:
  - host: yada.example.com
    username: bar
    password: never mind
    tags: [windows, abc_def]
  - host: yudu.example.com
    username: barbaz
    tags: [linux, foo]

Then the tags for the dummy.example.com execution environment are not updated. The same goes for the other attributes of the dummy.example.com execution environment.

Desired outcome

The new tags should be available after channel release.