[BUG] (nit) wording wrong in "create db" command with incompatible region/cloud

[tatu-at-datastax]

Describe the bug

When trying to create a DB with incompatible cloud/region, error is:

[INFO]  You are using a non-production environment 'TEST' 
REGION OK
[ERROR] Region 'us-east-1' is valid for cloud 'aws'. (InvalidRegionException)
[ERROR] Try 'astra help <your_command>' to get help
[INFO]  Run astra db list-regions-serverless or astra streaming list-regions to list available regions.

where 'is valid should instead be is not valid (or is invalid).

To Reproduce

astra db create DB_NAME -c aws --region us-east-1  --config TEST

Expected behavior

Error message would indicate there is a problem; right now it's mildly confusing.

Screenshots

Desktop (please complete the following information): MacOS 12.7.4

Additional context

N/A