Destroy of non-existing grant should not cause an error

[vladimirtiukhtin]

Terraform Version

Terraform v0.14.3
+ provider registry.terraform.io/terraform-providers/mysql v1.9.0

Affected Resource(s)

• mysql_grant

Expected Behavior

Non existing grant is a desired state, so terraform destroy should not exit with an error

Actual Behavior

Error: error revoking GRANT (REVOKE GRANT OPTION ON `*`.* FROM '*'@'*'): Error 1141: There is no such grant defined for user '*' on host '*'

Steps to Reproduce

1. Add mysql_grant resource
2. Run terraform apply
3. Delete the grant manually
4. Run terraform destroy