fix: Clarify explanation for ssl_certificates (#128)

Author: tpoindessous

README.md

@@ -117,7 +117,7 @@ Current version is 3.0. Upgrade guides:
 | quic | Set to `true` to enable QUIC support | bool | `"false"` | no |
 | security\_policy | The resource URL for the security policy to associate with the backend service | string | `"null"` | no |
 | ssl | Set to `true` to enable SSL support, requires variable `ssl_certificates` - a list of self_link certs | bool | `"false"` | no |
-| ssl\_certificates | SSL cert self_link list. Required if `ssl` is `true` and no `private_key` and `certificate` is provided. | list(string) | `<list>` | no |
+| ssl\_certificates | SSL cert self_link list. Required if `ssl` is `true` and `use_ssl_certificates` is `true`. | list(string) | `<list>` | no |
 | ssl\_policy | Selfink to SSL Policy | string | `"null"` | no |
 | target\_service\_accounts | List of target service accounts for health check firewall rule. Exactly one of target_tags or target_service_accounts should be specified. | list(string) | `<list>` | no |
 | target\_tags | List of target tags for health check firewall rule. Exactly one of target_tags or target_service_accounts should be specified. | list(string) | `<list>` | no |

variables.tf

@@ -170,7 +170,7 @@ variable "use_ssl_certificates" {
 }
 
 variable "ssl_certificates" {
-  description = "SSL cert self_link list. Required if `ssl` is `true` and no `private_key` and `certificate` is provided."
+  description = "SSL cert self_link list. Required if `ssl` is `true` and `use_ssl_certificates` is `true`."
   type        = list(string)
   default     = []
 }