Description of problem: hammer activation-key command failed to create or update when settings is disable, settings 'allow_multiple_content_views' need to be enabled prior to create or update ak.

It would be good if user get some warning message or hint inside the error message to turn settings ON while creating or updating ak.

How reproducible: Always

Is this issue a regression from an earlier version: No

Steps to Reproduce:

1. Execute command to create or update ak

1. hammer activation-key create --name="third_ak" --organization-id=1 --content-view-environments='LCE2/CV2,LCE1/CV1'
   Could not create the activation key:
     Assigning an activation key to multiple content view environments is not enabled.

Actual behavior:
No hint in error message to change settings 'allow_multiple_content_views'

Expected behavior:
Meaningful warning message along with error.

Business Impact / Additional info: