provider/aws: SG description should be ForceNew
provider/aws: SG description should be ForceNew

Description cannot be handled in Update (there is no ModifySecurityGroup
API call), so we have to recreate to change the description.

Closes #1870

terraform-providers/terraform-provider-aws,Ninir/terraform-provider-aws,terraform-providers/terraform-provider-aws,Ninir/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,ashinohara/terraform-provider-aws,kjmkznr/terraform-provider-aws,ClementCunin/terraform-provider-aws,terraform-providers/terraform-provider-aws,ClementCunin/terraform-provider-aws,nbaztec/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,nbaztec/terraform-provider-aws,kjmkznr/terraform-provider-aws,nbaztec/terraform-provider-aws,Ninir/terraform-provider-aws,nbaztec/terraform-provider-aws,ashinohara/terraform-provider-aws,ashinohara/terraform-provider-aws,terraform-providers/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,ClementCunin/terraform-provider-aws,ashinohara/terraform-provider-aws,Ninir/terraform-provider-aws,ClementCunin/terraform-provider-aws